cmake COMPILER_RT_HAS_WD4206_FLAG examples

Lewuathe/mlir-hello thirdparty/llvm-project/compiler-rt/cmake/config-ix.cmake :158

check_cxx_compiler_flag(/wd4206 COMPILER_RT_HAS_WD4206_FLAG)

CTSRD-CHERI/cheribsd contrib/subrepo-cheri-compiler-rt/cmake/config-ix.cmake :135

check_cxx_compiler_flag(/wd4206 COMPILER_RT_HAS_WD4206_FLAG)