fix compile fails with mingw32-w64-i686 compiler

Author: nayaku

CMakeLists.txt

@@ -8,7 +8,7 @@ project (raylib-lua-sol
 set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 configure_file(${CMAKE_SOURCE_DIR}/cmake/CTestCustom.cmake ${CMAKE_BINARY_DIR})
 
-if (WIN32)
+if (MSVC)
   #add_compile_options("/SUBSYSTEM:WINDOWS")
   #add_compile_options("/ENTRY:mainCRTStartup")
   #ADD_DEFINITIONS(/bigobj)