lavapipe: add some safety asserts when beginning rendering

if the render area exceeds the attachment size, this is not only illegal,
it will crash later

cc: mesa-stable

Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20583>

src/gallium/frontends/lavapipe/lvp_execute.c

@@ -1850,6 +1850,8 @@ static void handle_begin_rendering(struct vk_cmd_queue_entry *cmd,
             state->color_att[i].imgv = create_multisample_surface(state, imgv, state->forced_sample_count,
                                                                   att_needs_replicate(state, imgv, state->color_att[i].load_op));
          state->framebuffer.cbufs[i] = state->color_att[i].imgv->surface;
+         assert(state->render_area.offset.x + state->render_area.extent.width <= state->framebuffer.cbufs[i]->texture->width0);
+         assert(state->render_area.offset.y + state->render_area.extent.height <= state->framebuffer.cbufs[i]->texture->height0);
       } else {
          state->framebuffer.cbufs[i] = NULL;
       }
@@ -1881,6 +1883,8 @@ static void handle_begin_rendering(struct vk_cmd_queue_entry *cmd,
                                                      att_needs_replicate(state, imgv, load_op));
       }
       state->framebuffer.zsbuf = state->ds_imgv->surface;
+      assert(state->render_area.offset.x + state->render_area.extent.width <= state->framebuffer.zsbuf->texture->width0);
+      assert(state->render_area.offset.y + state->render_area.extent.height <= state->framebuffer.zsbuf->texture->height0);
    } else {
       state->ds_imgv = NULL;
       state->framebuffer.zsbuf = NULL;