This reverts commit 1bcdbd68616dc7f8debe126caafef7a7242a0e6b.
It's been reported that some bots are failing with this change with CMake
error like:
```
CMake Error at /b/s/w/ir/k/llvm-project/compiler-rt/cmake/config-ix.cmake:177 (message):
Unsupported architecture: arm64
Call Stack (most recent call first):
/b/s/w/ir/k/llvm-project/compiler-rt/cmake/config-ix.cmake:216 (get_target_flags_for_arch)
/b/s/w/ir/k/llvm-project/compiler-rt/test/tsan/CMakeLists.txt:78 (get_test_cflags_for_apple_platform)
```
I'm reverting the patch now to unbreak builds. I will investigate properly when time permits.
rdar://problem/50124489
llvm-svn: 359327
18bc872405