WINVER fixes for MinGW and VC++.

CMakeLists.txt

@@ -175,8 +175,9 @@ if (_GLFW_WIN32)
     # the inclusion of stddef.h (by glfw3.h), which is itself included before
     # win32_platform.h.  We define them here until a saner solution can be found
     # NOTE: MinGW-w64 and Visual C++ do /not/ need this hack.
-    add_definitions(-DUNICODE)
-    add_definitions(-DWINVER=0x0501)
+    if (CMAKE_COMPILER_IS_GNUC)
+        add_definitions(-DUNICODE -DWINVER=0x0501)
+    endif()
 endif()
 
 #--------------------------------------------------------------------

src/win32_platform.h

@@ -80,17 +80,18 @@
 #ifndef WM_COPYGLOBALDATA
  #define WM_COPYGLOBALDATA 0x0049
 #endif
-#ifndef MSGFLT_ALLOW
- #define MSGFLT_ALLOW 1
-#endif
 
-#if defined(__MINGW32__)
+#if WINVER < 0x0601
 typedef struct tagCHANGEFILTERSTRUCT
 {
     DWORD cbSize;
     DWORD ExtStatus;
+
 } CHANGEFILTERSTRUCT, *PCHANGEFILTERSTRUCT;
-#endif /*__MINGW32__*/
+#ifndef MSGFLT_ALLOW
+ #define MSGFLT_ALLOW 1
+#endif
+#endif /*Windows 7*/
 
 
 //========================================================================