ApplicationWin32/WindowWin32: Get/SetWindowLong -> Get/SetWindowLongPtr

Get/SetWindowLong is superseded on 64-bit Windows platform with
Get/SetWindowLongPtr. These are trivial to migrate over and have been
available since Windows 2000 Professional, so there's no need to worry
about breaking meaningful platform support

lib/win/Win32Common.hpp

@@ -39,8 +39,8 @@ struct OGLContext {
     size_t width, height;
 
     bool m_fs = false;
-    LONG m_fsStyle;
-    LONG m_fsExStyle;
+    LONG_PTR m_fsStyle;
+    LONG_PTR m_fsExStyle;
     RECT m_fsRect;
     int m_fsCountDown = 0;
   };