cmake COMPILER_RT_HAS_MCRC32_FLAG examples

Lewuathe/mlir-hello thirdparty/llvm-project/compiler-rt/cmake/config-ix.cmake :112

check_cxx_compiler_flag("-Werror -mcrc32"    COMPILER_RT_HAS_MCRC32_FLAG)

CTSRD-CHERI/cheribsd contrib/subrepo-cheri-compiler-rt/cmake/config-ix.cmake :90

check_cxx_compiler_flag("-Werror -mcrc32"    COMPILER_RT_HAS_MCRC32_FLAG)