cmake D_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER examples

Lewuathe/mlir-hello thirdparty/llvm-project/runtimes/cmake/Modules/WarningFlags.cmake :5 

target_compile_definitions(${target} PUBLIC -D_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)

PlatONnetwork/pWASM libc++/libcxx/CMakeLists.txt :477 

add_definitions(-D_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)