Update URLs from `master` to `main` branch. (#2335)

diff --git a/docs/GetStarted/getting_started_linux_bazel.md b/docs/GetStarted/getting_started_linux_bazel.md
index 738a365..8d4a9dc 100644
--- a/docs/GetStarted/getting_started_linux_bazel.md
+++ b/docs/GetStarted/getting_started_linux_bazel.md
@@ -20,7 +20,7 @@
 ### Install Bazel
 
 Install Bazel version > 2.0.0 (see
-[`.bazelversion`](https://github.com/google/iree/blob/master/.bazelversion) for
+[`.bazelversion`](https://github.com/google/iree/blob/main/.bazelversion) for
 the specific version IREE uses) by following the
 [official docs](https://docs.bazel.build/versions/master/install.html).
 
@@ -112,7 +112,7 @@
 ```
 
 Translate a
-[MLIR file](https://github.com/google/iree/blob/master/iree/tools/test/simple.mlir)
+[MLIR file](https://github.com/google/iree/blob/main/iree/tools/test/simple.mlir)
 and execute a function in the compiled module:
 
 ```shell
diff --git a/docs/GetStarted/getting_started_linux_cmake.md b/docs/GetStarted/getting_started_linux_cmake.md
index ed7856e..70da146 100644
--- a/docs/GetStarted/getting_started_linux_cmake.md
+++ b/docs/GetStarted/getting_started_linux_cmake.md
@@ -77,7 +77,7 @@
 
 > Tip:<br>
 > &nbsp;&nbsp;&nbsp;&nbsp;The root
-> [CMakeLists.txt](https://github.com/google/iree/blob/master/CMakeLists.txt)
+> [CMakeLists.txt](https://github.com/google/iree/blob/main/CMakeLists.txt)
 > file has options for configuring which parts of the project to enable.<br>
 > &nbsp;&nbsp;&nbsp;&nbsp;These are further documented in [CMake Options and Variables](cmake_options_and_variables.md).
 
@@ -99,7 +99,7 @@
 ```
 
 Translate a
-[MLIR file](https://github.com/google/iree/blob/master/iree/tools/test/simple.mlir)
+[MLIR file](https://github.com/google/iree/blob/main/iree/tools/test/simple.mlir)
 and execute a function in the compiled module:
 
 ```shell
diff --git a/docs/GetStarted/getting_started_linux_vulkan.md b/docs/GetStarted/getting_started_linux_vulkan.md
index 9ee8c61..5a0fd7f 100644
--- a/docs/GetStarted/getting_started_linux_vulkan.md
+++ b/docs/GetStarted/getting_started_linux_vulkan.md
@@ -39,7 +39,7 @@
 ### Quick Start
 
 The
-[dynamic_symbols_test](https://github.com/google/iree/blob/master/iree/hal/vulkan/dynamic_symbols_test.cc)
+[dynamic_symbols_test](https://github.com/google/iree/blob/main/iree/hal/vulkan/dynamic_symbols_test.cc)
 checks if the Vulkan loader and a valid ICD are accessible.
 
 Run the test:
@@ -58,7 +58,7 @@
 HAL, which includes checking for supported layers and extensions.
 
 Run the
-[device creation test](https://github.com/google/iree/blob/master/iree/hal/cts/device_creation_test.cc):
+[device creation test](https://github.com/google/iree/blob/main/iree/hal/cts/device_creation_test.cc):
 
 ```shell
 # -- CMake --
@@ -79,7 +79,7 @@
 SwiftShader's Vulkan ICD (Installable Client Driver).
 
 IREE has a
-[helper script](https://github.com/google/iree/blob/master/build_tools/third_party/swiftshader/build_vk_swiftshader.sh)
+[helper script](https://github.com/google/iree/blob/main/build_tools/third_party/swiftshader/build_vk_swiftshader.sh)
 for building SwiftShader from source using CMake:
 
 ```shell
diff --git a/docs/GetStarted/getting_started_macos_bazel.md b/docs/GetStarted/getting_started_macos_bazel.md
index a169f8d..2b285eb 100644
--- a/docs/GetStarted/getting_started_macos_bazel.md
+++ b/docs/GetStarted/getting_started_macos_bazel.md
@@ -115,7 +115,7 @@
 ```
 
 Translate a
-[MLIR file](https://github.com/google/iree/blob/master/iree/tools/test/simple.mlir)
+[MLIR file](https://github.com/google/iree/blob/main/iree/tools/test/simple.mlir)
 and execute a function in the compiled module:
 
 ```shell
diff --git a/docs/GetStarted/getting_started_macos_cmake.md b/docs/GetStarted/getting_started_macos_cmake.md
index 59d22e8..51ef0ab 100644
--- a/docs/GetStarted/getting_started_macos_cmake.md
+++ b/docs/GetStarted/getting_started_macos_cmake.md
@@ -77,7 +77,7 @@
 
 > Tip:<br>
 > &nbsp;&nbsp;&nbsp;&nbsp;The root
-> [CMakeLists.txt](https://github.com/google/iree/blob/master/CMakeLists.txt)
+> [CMakeLists.txt](https://github.com/google/iree/blob/main/CMakeLists.txt)
 > file has options for configuring which parts of the project to enable.<br>
 > &nbsp;&nbsp;&nbsp;&nbsp;These are further documented in [CMake Options and Variables](cmake_options_and_variables.md).
 
@@ -99,7 +99,7 @@
 ```
 
 Translate a
-[MLIR file](https://github.com/google/iree/blob/master/iree/tools/test/simple.mlir)
+[MLIR file](https://github.com/google/iree/blob/main/iree/tools/test/simple.mlir)
 and execute a function in the compiled module:
 
 ```shell
diff --git a/docs/GetStarted/getting_started_python.md b/docs/GetStarted/getting_started_python.md
index 627dd3d..1a0452b 100644
--- a/docs/GetStarted/getting_started_python.md
+++ b/docs/GetStarted/getting_started_python.md
@@ -61,9 +61,9 @@
 ## Using Colab
 
 See
-[start_colab_kernel.py](https://github.com/google/iree/blob/master/colab/start_colab_kernel.py)
+[start_colab_kernel.py](https://github.com/google/iree/blob/main/colab/start_colab_kernel.py)
 and
-[Using Colab](https://github.com/google/iree/blob/master/docs/using_colab.md)
+[Using Colab](https://github.com/google/iree/blob/main/docs/using_colab.md)
 for setup instructions, then take a look through the
-[Colab directory](https://github.com/google/iree/tree/master/colab) for some
+[Colab directory](https://github.com/google/iree/tree/main/colab) for some
 sample notebooks.
diff --git a/docs/GetStarted/getting_started_windows_bazel.md b/docs/GetStarted/getting_started_windows_bazel.md
index 3eb660d..d3f01c3 100644
--- a/docs/GetStarted/getting_started_windows_bazel.md
+++ b/docs/GetStarted/getting_started_windows_bazel.md
@@ -25,7 +25,7 @@
 ### Install Bazel
 
 Install Bazel version > 2.0.0 (see
-[`.bazelversion`](https://github.com/google/iree/blob/master/.bazelversion) for
+[`.bazelversion`](https://github.com/google/iree/blob/main/.bazelversion) for
 the specific version IREE uses) by following the
 [official docs](https://docs.bazel.build/versions/master/install-windows.html).
 
@@ -108,7 +108,7 @@
 ```
 
 Translate a
-[MLIR file](https://github.com/google/iree/blob/master/iree/tools/test/simple.mlir)
+[MLIR file](https://github.com/google/iree/blob/main/iree/tools/test/simple.mlir)
 and execute a function in the compiled module:
 
 ```powershell
diff --git a/docs/GetStarted/getting_started_windows_cmake.md b/docs/GetStarted/getting_started_windows_cmake.md
index 77d4fe4..dcab418 100644
--- a/docs/GetStarted/getting_started_windows_cmake.md
+++ b/docs/GetStarted/getting_started_windows_cmake.md
@@ -75,7 +75,7 @@
 
 > Tip:<br>
 > &nbsp;&nbsp;&nbsp;&nbsp;The root
-> [CMakeLists.txt](https://github.com/google/iree/blob/master/CMakeLists.txt)
+> [CMakeLists.txt](https://github.com/google/iree/blob/main/CMakeLists.txt)
 > file has options for configuring which parts of the project to enable.<br>
 > &nbsp;&nbsp;&nbsp;&nbsp;These are further documented in [CMake Options and Variables](cmake_options_and_variables.md).
 
@@ -97,7 +97,7 @@
 ```
 
 Translate a
-[MLIR file](https://github.com/google/iree/blob/master/iree/tools/test/simple.mlir)
+[MLIR file](https://github.com/google/iree/blob/main/iree/tools/test/simple.mlir)
 and execute a function in the compiled module:
 
 ```powershell
diff --git a/docs/GetStarted/getting_started_windows_vulkan.md b/docs/GetStarted/getting_started_windows_vulkan.md
index 9ceee2a..4e6c7b9 100644
--- a/docs/GetStarted/getting_started_windows_vulkan.md
+++ b/docs/GetStarted/getting_started_windows_vulkan.md
@@ -39,7 +39,7 @@
 ### Quick Start
 
 The
-[dynamic_symbols_test](https://github.com/google/iree/blob/master/iree/hal/vulkan/dynamic_symbols_test.cc)
+[dynamic_symbols_test](https://github.com/google/iree/blob/main/iree/hal/vulkan/dynamic_symbols_test.cc)
 checks if the Vulkan loader and a valid ICD are accessible.
 
 Run the test:
@@ -58,7 +58,7 @@
 HAL, which includes checking for supported layers and extensions.
 
 Run the
-[device creation test](https://github.com/google/iree/blob/master/iree/hal/cts/device_creation_test.cc):
+[device creation test](https://github.com/google/iree/blob/main/iree/hal/cts/device_creation_test.cc):
 
 ```powershell
 # -- CMake --
diff --git a/docs/developer_overview.md b/docs/developer_overview.md
index 7ab969b..f23cd89 100644
--- a/docs/developer_overview.md
+++ b/docs/developer_overview.md
@@ -5,48 +5,48 @@
 
 ## Project Code Layout
 
-[iree/](https://github.com/google/iree/blob/master/iree/)
+[iree/](https://github.com/google/iree/blob/main/iree/)
 
 *   Core IREE project
 
-[integrations/](https://github.com/google/iree/blob/master/integrations/)
+[integrations/](https://github.com/google/iree/blob/main/integrations/)
 
 *   Integrations between IREE and other frameworks, such as TensorFlow
 
-[bindings/](https://github.com/google/iree/blob/master/bindings/)
+[bindings/](https://github.com/google/iree/blob/main/bindings/)
 
 *   Language and platform bindings, such as Python
 
-[colab/](https://github.com/google/iree/blob/master/colab/)
+[colab/](https://github.com/google/iree/blob/main/colab/)
 
 *   Colab notebooks for interactively using IREE's Python bindings
 
 ## IREE Code Layout
 
-[iree/base/](https://github.com/google/iree/blob/master/iree/base/)
+[iree/base/](https://github.com/google/iree/blob/main/iree/base/)
 
 *   Common types and utilities used throughout IREE
 
-[iree/compiler/](https://github.com/google/iree/blob/master/iree/compiler/)
+[iree/compiler/](https://github.com/google/iree/blob/main/iree/compiler/)
 
 *   IREE's MLIR dialects, LLVM compiler passes, module translation code, etc.
     Code here should not depend on anything in the runtime
 
-[iree/hal/](https://github.com/google/iree/blob/master/iree/hal/)
+[iree/hal/](https://github.com/google/iree/blob/main/iree/hal/)
 
 *   **H**ardware **A**bstraction **L**ayer for IREE's runtime, with
     implementations for hardware and software backends
 
-[iree/schemas/](https://github.com/google/iree/blob/master/iree/schemas/)
+[iree/schemas/](https://github.com/google/iree/blob/main/iree/schemas/)
 
 *   Shared data storage format definitions, primarily using
     [FlatBuffers](https://google.github.io/flatbuffers/)
 
-[iree/tools/](https://github.com/google/iree/blob/master/iree/tools/)
+[iree/tools/](https://github.com/google/iree/blob/main/iree/tools/)
 
 *   Assorted tools used to optimize, translate, and evaluate IREE
 
-[iree/vm/](https://github.com/google/iree/blob/master/iree/vm/)
+[iree/vm/](https://github.com/google/iree/blob/main/iree/vm/)
 
 *   Bytecode **V**irtual **M**achine used to work with IREE modules and invoke
     IREE functions
@@ -77,7 +77,7 @@
 `FileCheck` should be used to test the generated output.
 
 Here's an example of a small compiler pass running on a
-[test file](https://github.com/google/iree/blob/master/iree/compiler/Dialect/IREE/Transforms/test/drop_compiler_hints.mlir):
+[test file](https://github.com/google/iree/blob/main/iree/compiler/Dialect/IREE/Transforms/test/drop_compiler_hints.mlir):
 
 ```shell
 $ bazel run iree/tools:iree-opt -- \
@@ -89,7 +89,7 @@
 
 For a more complex example, here's how to run IREE's complete transformation
 pipeline targeting the VMLA backend on the
-[fullyconnected.mlir](https://github.com/google/iree/blob/master/iree/test/e2e/models/fullyconnected.mlir)
+[fullyconnected.mlir](https://github.com/google/iree/blob/main/iree/test/e2e/models/fullyconnected.mlir)
 model file:
 
 ```shell
@@ -100,7 +100,7 @@
 ```
 
 Custom passes may also be layered on top of `iree-opt`, see
-[iree/samples/custom_modules/dialect](https://github.com/google/iree/blob/master/iree/samples/custom_modules/dialect)
+[iree/samples/custom_modules/dialect](https://github.com/google/iree/blob/main/iree/samples/custom_modules/dialect)
 for a sample.
 
 ### iree-translate
@@ -123,7 +123,7 @@
 ```
 
 Custom translations may also be layered on top of `iree-translate`, see
-[iree/samples/custom_modules/dialect](https://github.com/google/iree/blob/master/iree/samples/custom_modules/dialect)
+[iree/samples/custom_modules/dialect](https://github.com/google/iree/blob/main/iree/samples/custom_modules/dialect)
 for a sample.
 
 ### iree-run-module
@@ -150,7 +150,7 @@
 and executes it as a series of
 [googletest](https://github.com/google/googletest) tests. This is the test
 runner for the IREE
-[check framework](https://github.com/google/iree/tree/master/docs/testing_guide.md#end-to-end-tests).
+[check framework](https://github.com/google/iree/tree/main/docs/testing_guide.md#end-to-end-tests).
 
 ```shell
 $ bazel run iree/tools:iree-translate -- \
@@ -176,7 +176,7 @@
 function as exported by default and running all of them.
 
 For example, to execute the contents of
-[iree/tools/test/simple.mlir](https://github.com/google/iree/blob/master/iree/tools/test/simple.mlir):
+[iree/tools/test/simple.mlir](https://github.com/google/iree/blob/main/iree/tools/test/simple.mlir):
 
 ```shell
 $ bazel run iree/tools:iree-run-mlir -- \
@@ -210,7 +210,7 @@
 ### Useful Vulkan driver flags
 
 For IREE's Vulkan runtime driver, there are a few useful
-[flags](https://github.com/google/iree/blob/master/iree/hal/vulkan/vulkan_driver.cc):
+[flags](https://github.com/google/iree/blob/main/iree/hal/vulkan/vulkan_driver.cc):
 
 #### `--vulkan_renderdoc`
 
diff --git a/docs/repository_management.md b/docs/repository_management.md
index 567b947..df769f7 100644
--- a/docs/repository_management.md
+++ b/docs/repository_management.md
@@ -33,7 +33,7 @@
 of truth for the correct submodule state and is what is used by the CI. When
 updating the submodule state from Google's source repository, only this file is
 updated and another
-[GitHub Actions workflow](https://github.com/google/iree/blob/master/.github/workflows/synchronize_submodules.yml)
+[GitHub Actions workflow](https://github.com/google/iree/blob/main/.github/workflows/synchronize_submodules.yml)
 immediately commits a submodule update on top of that.
 
 Shortcut commands (read below for full documentation):
diff --git a/docs/testing_guide.md b/docs/testing_guide.md
index 8819f54..ce1ea4c 100644
--- a/docs/testing_guide.md
+++ b/docs/testing_guide.md
@@ -11,7 +11,7 @@
 
 ### Running a Test
 
-For the test https://github.com/google/iree/tree/master/iree/base/arena_test.cc
+For the test https://github.com/google/iree/tree/main/iree/base/arena_test.cc
 
 With CMake, run this from the build directory:
 
@@ -78,7 +78,7 @@
 
 We have created a corresponding CMake function `iree_cc_test` that mirrors the
 Bazel rule's behavior. Our
-[Bazel to CMake converter](https://github.com/google/iree/tree/master/build_tools/bazel_to_cmake/bazel_to_cmake.py)
+[Bazel to CMake converter](https://github.com/google/iree/tree/main/build_tools/bazel_to_cmake/bazel_to_cmake.py)
 should generally derive the `CMakeLists.txt` file from the BUILD file:
 
 ```cmake
@@ -101,7 +101,7 @@
 ### Running a Test
 
 For the test
-https://github.com/google/iree/tree/master/iree/compiler/Dialect/VMLA/Conversion/HLOToVMLA/test/math_ops.mlir
+https://github.com/google/iree/tree/main/iree/compiler/Dialect/VMLA/Conversion/HLOToVMLA/test/math_ops.mlir
 
 With CMake, run this from the build directory:
 
@@ -123,7 +123,7 @@
 are testing. Instead of `mlir-opt`, use `iree-opt`, which registers IREE
 dialects and passes and doesn't register some unnecessary core ones. Instead of
 `FileCheck`, use
-[`IreeFileCheck`](https://github.com/google/iree/tree/master/iree/tools/IreeFileCheck.sh),
+[`IreeFileCheck`](https://github.com/google/iree/tree/main/iree/tools/IreeFileCheck.sh),
 a shell-script wrapper around FileCheck that passes it a few
 `--do-the-right-thing` flags.
 
@@ -150,7 +150,7 @@
 ```
 
 There is a corresponding CMake function, calls to which will be generated by our
-[Bazel to CMake Converter](https://github.com/google/iree/tree/master/build_tools/bazel_to_cmake/bazel_to_cmake.py).
+[Bazel to CMake Converter](https://github.com/google/iree/tree/main/build_tools/bazel_to_cmake/bazel_to_cmake.py).
 
 ```cmake
 file(GLOB _GLOB_X_MLIR LIST_DIRECTORIES false RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} CONFIGURE_DEPENDS *.mlir)
@@ -184,7 +184,7 @@
 ### Running a Test
 
 For the test
-https://github.com/google/iree/tree/master/iree/test/e2e/xla_ops/floor.mlir
+https://github.com/google/iree/tree/main/iree/test/e2e/xla_ops/floor.mlir
 compiled for the VMLA target backend and running on the VMLA driver (here they
 match exactly, but in principle there's a many-to-many mapping from backends to
 drivers).
@@ -363,7 +363,7 @@
 
 The CMake functions follow a similar pattern. The calls to them are generated in
 our `CMakeLists.txt` file by
-[bazel_to_cmake](https://github.com/google/iree/tree/master/build_tools/bazel_to_cmake/bazel_to_cmake.py).
+[bazel_to_cmake](https://github.com/google/iree/tree/main/build_tools/bazel_to_cmake/bazel_to_cmake.py).
 
 ## Binding Tests