windows: Use wglSwapLayerBuffers if available.

It apparently works better (or can work better?) on multimonitor setups
than SwapBuffers.

This should be available back to Windows 95, but just in case, it falls
back to standard SwapBuffers if not available.

Fixes #13269.

src/video/windows/SDL_windowsopengl.c

@@ -141,6 +141,9 @@ bool WIN_GL_LoadLibrary(SDL_VideoDevice *_this, const char *path)
         SDL_LoadFunction(handle, "wglMakeCurrent");
     _this->gl_data->wglShareLists = (BOOL (WINAPI *)(HGLRC, HGLRC))
         SDL_LoadFunction(handle, "wglShareLists");
+    _this->gl_data->wglSwapLayerBuffers = (BOOL (WINAPI *)(HDC, UINT))
+        SDL_LoadFunction(handle, "wglSwapLayerBuffers");
+
     /* *INDENT-ON* */ // clang-format on
 
 #if defined(SDL_PLATFORM_XBOXONE) || defined(SDL_PLATFORM_XBOXSERIES)
@@ -886,8 +889,14 @@ bool WIN_GL_SwapWindow(SDL_VideoDevice *_this, SDL_Window *window)
 {
     HDC hdc = window->internal->hdc;
 
-    if (!SwapBuffers(hdc)) {
-        return WIN_SetError("SwapBuffers()");
+    if (_this->gl_data->wglSwapLayerBuffers) {
+        if (!_this->gl_data->wglSwapLayerBuffers(hdc, WGL_SWAP_MAIN_PLANE)) {
+            return WIN_SetError("wglSwapLayerBuffers()");
+        }
+    } else {
+        if (!SwapBuffers(hdc)) {
+            return WIN_SetError("SwapBuffers()");
+        }
     }
     return true;
 }

src/video/windows/SDL_windowsopengl.h

@@ -85,6 +85,8 @@ struct SDL_GLDriverData
     BOOL (WINAPI *wglGetPixelFormatAttribivARB)(HDC hdc, int iPixelFormat, int iLayerPlane, UINT nAttributes, const int *piAttributes, int *piValues);
     BOOL (WINAPI *wglSwapIntervalEXT)(int interval);
     int (WINAPI *wglGetSwapIntervalEXT)(void);
+    BOOL (WINAPI *wglSwapLayerBuffers)(HDC hdc, UINT flags);
+
 #if defined(SDL_PLATFORM_XBOXONE) || defined(SDL_PLATFORM_XBOXSERIES)
     BOOL (WINAPI *wglSwapBuffers)(HDC hdc);
     int (WINAPI *wglDescribePixelFormat)(HDC hdc,