[sanitizers] Pass CMAKE_C_FLAGS into TSan buildgo script

[sanitizers] Pass CMAKE_C_FLAGS into TSan buildgo script

When compiling with ccache, compiler commands get split into smaller steps
and clang's default -Wunused-command-line-argument complains about unused
include directory arguments. In combination -Werror, compilation aborts.

If CMAKE_C_FLAGS contains -Wno-unused-command-line-argument or
-Wno-error=unused-command-line-argument, the latter flag is passed into the
build script.

This is a re-commit. The previous version was reverted because of failing
tests.

Differential Revision: https://reviews.llvm.org/D96762