message: Fix unknown warning "no-deprecated-copy" on Apple
  Compile fix for MacOS Catalina
diff: @@ -126,7 +126,7 @@ if(CMAKE_COMPILER_IS_GNUCXX AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 6.9)
  endif()
  if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
  - set_property(SOURCE "${glslang_sources}"
  + set_property(SOURCE ${glslang_sources}
  APPEND_STRING PROPERTY COMPILE_FLAGS " -Wno-unknown-warning-option")
  if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 9.9)
  