CMake: Don't use /NODEFAULTLIB on Windows unless we're Visual Studio.

CMakeLists.txt

@@ -1256,7 +1256,7 @@ if(SDL_STATIC)
   set (BUILD_SHARED_LIBS FALSE)
   add_library(SDL2-static STATIC ${SOURCE_FILES})
   set_target_properties(SDL2-static PROPERTIES OUTPUT_NAME "SDL2")
-  if(WINDOWS)
+  if(MSVC)
     set_target_properties(SDL2-static PROPERTIES LINK_FLAGS_RELEASE "/NODEFAULTLIB")
     set_target_properties(SDL2-static PROPERTIES LINK_FLAGS_DEBUG "/NODEFAULTLIB")
     set_target_properties(SDL2-static PROPERTIES STATIC_LIBRARY_FLAGS "/NODEFAULTLIB")