Adding Wunused-local-typedef build flag (pytorch#86154)

# Summary

In the past, we have seen PRs causing internal breakages caused by `-Wunused-local-typedef` flag which than had to be fixed. For example: [pytorch#79978](pytorch#79978)

As part of this change, we want to catch this error in the PR Checks itself.

Pull Request resolved: pytorch#86154
Approved by: https://github.com/huydhn, https://github.com/seemethere, https://github.com/osalpekar

Author: mehtanirav

CMakeLists.txt

@@ -832,6 +832,7 @@ if(NOT MSVC)
   append_cxx_flag_if_supported("-Wno-type-limits" CMAKE_CXX_FLAGS)
   append_cxx_flag_if_supported("-Wno-array-bounds" CMAKE_CXX_FLAGS)
   append_cxx_flag_if_supported("-Wno-unknown-pragmas" CMAKE_CXX_FLAGS)
+  append_cxx_flag_if_supported("-Wunused-local-typedefs" CMAKE_CXX_FLAGS)
   append_cxx_flag_if_supported("-Wno-unused-parameter" CMAKE_CXX_FLAGS)
   append_cxx_flag_if_supported("-Wno-unused-function" CMAKE_CXX_FLAGS)
   append_cxx_flag_if_supported("-Wno-unused-result" CMAKE_CXX_FLAGS)
@@ -895,6 +896,7 @@ if(NOT MSVC)
     append_cxx_flag_if_supported("-Wno-constexpr-not-const" CMAKE_CXX_FLAGS)
     append_cxx_flag_if_supported("-Wno-missing-braces" CMAKE_CXX_FLAGS)
     append_cxx_flag_if_supported("-Wunused-lambda-capture" CMAKE_CXX_FLAGS)
+    append_cxx_flag_if_supported("-Wunused-local-typedef" CMAKE_CXX_FLAGS)
     append_cxx_flag_if_supported("-Qunused-arguments" CMAKE_CXX_FLAGS)
     if(${USE_COLORIZE_OUTPUT})
     endif()

defs.bzl

@@ -15,7 +15,6 @@ default_compiler_flags = [
     "-Wno-unused-function",
     "-Wno-unused-parameter",
     "-Wno-error=strict-aliasing",
-    "-Wno-unused-local-typedefs",
     "-Wno-shadow-compatible-local",
     "-Wno-maybe-uninitialized",  # aten is built with gcc as part of HHVM
     "-Wno-unknown-pragmas",