cmake COMPILER_RT_HAS_WD4221_FLAG examples

Lewuathe/mlir-hello thirdparty/llvm-project/compiler-rt/cmake/config-ix.cmake :160 

check_cxx_compiler_flag(/wd4221 COMPILER_RT_HAS_WD4221_FLAG)

trailofbits/polytracker polytracker/src/compiler-rt/cmake/config-ix.cmake :116 

check_cxx_compiler_flag(/wd4221 COMPILER_RT_HAS_WD4221_FLAG)

CTSRD-CHERI/cheribsd contrib/subrepo-cheri-compiler-rt/cmake/config-ix.cmake :137 

check_cxx_compiler_flag(/wd4221 COMPILER_RT_HAS_WD4221_FLAG)