Enable MS language extension on Clang and GCC

CMakeLists.txt

@@ -59,7 +59,9 @@ option(GLM_TEST_ENABLE_LANG_EXTENSIONS "Enable language extensions" OFF)
 
 if(GLM_TEST_ENABLE_LANG_EXTENSIONS)
 	set(CMAKE_CXX_EXTENSIONS ON)
-	if(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
+	if((CMAKE_CXX_COMPILER_ID MATCHES "Clang") OR (CMAKE_CXX_COMPILER_ID MATCHES "GNU"))
+		add_compile_options(-fms-extensions)
+	elseif(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
 		add_compile_options(/Ze)
 	endif()
 	message(STATUS "GLM: Build with C++ language extensions")