[compiler-rt] [compiler-rt][test] Apply CFLAGS from sanitizer_common to all tests (PR #120798)

[Aaron Puchert via llvm-commits]

aaronpuchert wrote:

@gulfemsavrun, can you explain how this impacts your build configuration? Do you use `CMAKE_SYSROOT`? I don't see any in the log, so I presume not? So I wonder what changed here.

As a side note, it's really annoying that whatever I do in `compiler-rt`, I get my change reverted by Google because it breaks some obscure build configuration that is not covered by the build bots. This change is already trying to fix an issue that caused a previous revert, and as you can see, I got zero feedback for half a year from the people who reverted my original change. (The change was arguably correct, but `--sysroot` was applied only to some to some tests, which caused a failure with certain sysroots.)

https://github.com/llvm/llvm-project/pull/120798