Yet more Win64 tweaks

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%401485

src/video/wincommon/SDL_lowvideo.h

@@ -39,6 +39,9 @@
 #ifndef GWLP_WNDPROC
 #define GWLP_WNDPROC	GWL_WNDPROC
 #endif
+#ifndef GCLP_HICON
+#define GCLP_HICON GCL_HICON
+#endif
 
 #include "../SDL_sysvideo.h"
 
@@ -118,7 +121,7 @@ extern void DX5_SoundFocus(HWND window);
 
 /* DJM: This is really from SDL_sysevents.c, we need it in
    GDL_CreateWindow as well */
-LONG CALLBACK WinMessage(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);
+LRESULT CALLBACK WinMessage(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);
 
 /* JFP: Implementation of ToUnicode() that works on 9x/ME/2K/XP */
 typedef int (WINAPI *ToUnicodeFN)(UINT, UINT, PBYTE, LPWSTR, int, UINT);

src/video/wincommon/SDL_syswm.c

@@ -220,7 +220,7 @@ void WIN_SetWMIcon(_THIS, SDL_Surface *icon, Uint8 *mask)
 	if ( screen_icn == NULL ) {
 		SDL_SetError("Couldn't create Win32 icon handle");
 	} else {
-		SetClassLongPtr(SDL_Window, GCL_HICON, (LONG_PTR)screen_icn);
+		SetClassLongPtr(SDL_Window, GCLP_HICON, (LONG_PTR)screen_icn);
 	}
 	SDL_stack_free(icon_win32);
 #endif /* DISABLE_ICON_SUPPORT */