egl/kopper: Pass ancillary invalidate flush flags down to gallium.

We can just add the flags to the kopper interface, since it's private to
Mesa.  This gets us depth/stencil invalidation on swapbuffers, which is
critical for tiler performance.

glmark2-es2 -b texture (windowed) goes from 1650 to 1930 fps on
zink+turnip with ZINK_DEBUG=rp.

Part of #7321 (we're still a little behind freedreno's 2180 fps)

Reviewed-by: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21317>

include/kopper_interface.h

@@ -61,7 +61,8 @@ struct __DRIkopperExtensionRec {
                                         const __DRIconfig *config,
                                         void *loaderPrivate,
                                         int pixmap);
-    int64_t (*swapBuffers)(__DRIdrawable *draw);
+    /* flags is a set of __DRI2_FLUSH_* flags */
+    int64_t (*swapBuffers)(__DRIdrawable *draw, uint32_t flush_flags);
     void (*setSwapInterval)(__DRIdrawable *drawable, int interval);
     int (*queryBufferAge)(__DRIdrawable *drawable);
 };