[metal] NFC: Simplify file names by dropping `metal_` prefix (#14270)

These file names contain Metal specific concepts; so there is no need to
prefix with `metal_` to disambiguate.
diff --git a/experimental/metal/CMakeLists.txt b/experimental/metal/CMakeLists.txt
index 9552b58..88b7503 100644
--- a/experimental/metal/CMakeLists.txt
+++ b/experimental/metal/CMakeLists.txt
@@ -23,18 +23,18 @@
     "direct_allocator.m"
     "direct_command_buffer.h"
     "direct_command_buffer.m"
+    "kernel_library.h"
+    "kernel_library.m"
     "metal_buffer.h"
     "metal_buffer.m"
     "metal_device.m"
     "metal_driver.m"
-    "metal_kernel_library.h"
-    "metal_kernel_library.m"
-    "metal_shared_event.h"
-    "metal_shared_event.m"
     "nop_executable_cache.h"
     "nop_executable_cache.m"
     "pipeline_layout.h"
     "pipeline_layout.m"
+    "shared_event.h"
+    "shared_event.m"
     "staging_buffer.h"
     "staging_buffer.m"
   DEPS
diff --git a/experimental/metal/README.md b/experimental/metal/README.md
index 0ca61ac..5eecd36 100644
--- a/experimental/metal/README.md
+++ b/experimental/metal/README.md
@@ -326,8 +326,8 @@
 [hal-semaphore]: https://github.com/openxla/iree/blob/main/runtime/src/iree/hal/semaphore.h
 [metal-device]: https://github.com/openxla/iree/tree/main/experimental/metal/metal_device.h
 [metal-driver]: https://github.com/openxla/iree/tree/main/experimental/metal/metal_driver.h
-[metal-kernel-library]: https://github.com/openxla/iree/tree/main/experimental/metal/metal_kernel_library.h
-[metal-shared-event]: https://github.com/openxla/iree/tree/main/experimental/metal/metal_shared_event.h
+[metal-kernel-library]: https://github.com/openxla/iree/tree/main/experimental/metal/kernel_library.h
+[metal-shared-event]: https://github.com/openxla/iree/tree/main/experimental/metal/shared_event.h
 [metal-spirv-target]: https://github.com/openxla/iree/tree/main/compiler/src/iree/compiler/Dialect/HAL/Target/MetalSPIRV
 [metal-builtin-kernels]: https://github.com/openxla/iree/tree/main/experimental/metal/builtin/
 [mtl-argument-buffer]: https://developer.apple.com/documentation/metal/buffers/about_argument_buffers?language=objc
diff --git a/experimental/metal/builtin_executables.h b/experimental/metal/builtin_executables.h
index 5c9c07e..a50ba6f 100644
--- a/experimental/metal/builtin_executables.h
+++ b/experimental/metal/builtin_executables.h
@@ -9,7 +9,7 @@
 
 #import <Metal/Metal.h>
 
-#include "experimental/metal/metal_kernel_library.h"
+#include "experimental/metal/kernel_library.h"
 #include "iree/base/api.h"
 #include "iree/hal/api.h"
 
diff --git a/experimental/metal/direct_command_buffer.m b/experimental/metal/direct_command_buffer.m
index c504219..1df4f91 100644
--- a/experimental/metal/direct_command_buffer.m
+++ b/experimental/metal/direct_command_buffer.m
@@ -9,9 +9,9 @@
 #import <Metal/Metal.h>
 
 #include "experimental/metal/builtin_executables.h"
+#include "experimental/metal/kernel_library.h"
 #include "experimental/metal/metal_buffer.h"
 #include "experimental/metal/metal_device.h"
-#include "experimental/metal/metal_kernel_library.h"
 #include "experimental/metal/pipeline_layout.h"
 #include "experimental/metal/staging_buffer.h"
 #include "iree/base/api.h"
diff --git a/experimental/metal/metal_kernel_library.h b/experimental/metal/kernel_library.h
similarity index 100%
rename from experimental/metal/metal_kernel_library.h
rename to experimental/metal/kernel_library.h
diff --git a/experimental/metal/metal_kernel_library.m b/experimental/metal/kernel_library.m
similarity index 99%
rename from experimental/metal/metal_kernel_library.m
rename to experimental/metal/kernel_library.m
index a31aad8..156b7d3 100644
--- a/experimental/metal/metal_kernel_library.m
+++ b/experimental/metal/kernel_library.m
@@ -4,7 +4,7 @@
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#include "experimental/metal/metal_kernel_library.h"
+#include "experimental/metal/kernel_library.h"
 
 #include <stddef.h>
 
diff --git a/experimental/metal/metal_device.m b/experimental/metal/metal_device.m
index 1b7122b..e01442c 100644
--- a/experimental/metal/metal_device.m
+++ b/experimental/metal/metal_device.m
@@ -10,9 +10,9 @@
 #include "experimental/metal/builtin_executables.h"
 #include "experimental/metal/direct_allocator.h"
 #include "experimental/metal/direct_command_buffer.h"
-#include "experimental/metal/metal_shared_event.h"
 #include "experimental/metal/nop_executable_cache.h"
 #include "experimental/metal/pipeline_layout.h"
+#include "experimental/metal/shared_event.h"
 #include "experimental/metal/staging_buffer.h"
 #include "iree/base/api.h"
 #include "iree/base/tracing.h"
diff --git a/experimental/metal/nop_executable_cache.m b/experimental/metal/nop_executable_cache.m
index ae6926d..ace2c82 100644
--- a/experimental/metal/nop_executable_cache.m
+++ b/experimental/metal/nop_executable_cache.m
@@ -10,7 +10,7 @@
 #include <stdbool.h>
 #include <stddef.h>
 
-#include "experimental/metal/metal_kernel_library.h"
+#include "experimental/metal/kernel_library.h"
 #include "iree/base/api.h"
 #include "iree/base/tracing.h"
 
diff --git a/experimental/metal/metal_shared_event.h b/experimental/metal/shared_event.h
similarity index 100%
rename from experimental/metal/metal_shared_event.h
rename to experimental/metal/shared_event.h
diff --git a/experimental/metal/metal_shared_event.m b/experimental/metal/shared_event.m
similarity index 99%
rename from experimental/metal/metal_shared_event.m
rename to experimental/metal/shared_event.m
index f49a4f4..796707f 100644
--- a/experimental/metal/metal_shared_event.m
+++ b/experimental/metal/shared_event.m
@@ -4,7 +4,7 @@
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#include "experimental/metal/metal_shared_event.h"
+#include "experimental/metal/shared_event.h"
 
 #import <Metal/Metal.h>