cmake LIBOMP_HAVE_WRETURN_TYPE_C_LINKAGE_FLAG examples

Lewuathe/mlir-hello thirdparty/llvm-project/openmp/runtime/cmake/config-ix.cmake :67

check_cxx_compiler_flag(-Wreturn-type-c-linkage LIBOMP_HAVE_WRETURN_TYPE_C_LINKAGE_FLAG)