Misc build and source fixes to get //iree/base/... building/testing under bazel.

Still need to do some corresponding submodule maintenance (will do in a separate PR).

PiperOrigin-RevId: 273773161
diff --git a/WORKSPACE b/WORKSPACE
index 4669781..4e14c08 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -1 +1,38 @@
 # Workspace file for the IREE project.
+workspace(name = "iree")
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+# Abseil depends on starlark rules that are currently maintained outside
+# of Bazel.
+# Source: https://github.com/abseil/abseil-cpp/blob/master/WORKSPACE
+http_archive(
+    name = "rules_cc",
+    sha256 = "67412176974bfce3f4cf8bdaff39784a72ed709fc58def599d1f68710b58d68b",
+    strip_prefix = "rules_cc-b7fe9697c0c76ab2fd431a891dbb9a6a32ed7c3e",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/rules_cc/archive/b7fe9697c0c76ab2fd431a891dbb9a6a32ed7c3e.zip",
+        "https://github.com/bazelbuild/rules_cc/archive/b7fe9697c0c76ab2fd431a891dbb9a6a32ed7c3e.zip",
+    ],
+)
+
+local_repository(
+    name = "com_google_absl",
+    path = "third_party/abseil-cpp",
+)
+
+local_repository(
+    name = "com_google_googletest",
+    path = "third_party/googletest",
+)
+
+local_repository(
+    name = "flatbuffers",
+    path = "third_party/flatbuffers",
+)
+
+new_local_repository(
+    name = "com_google_tracing_framework_cpp",
+    path = "third_party/google_tracing_framework/bindings/cpp",
+    build_file = "build_tools/third_party/google_tracing_framework_cpp/BUILD.bazel",
+)