st/mesa: don't use the PBO GetTexImage compute shader for 64K textures

I uses uint16_t for width/height.

Reviewed-by: Qiang Yu <yuq825@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/38587>

src/mesa/state_tracker/st_pbo_compute.c

@@ -1304,11 +1304,12 @@ st_GetTexSubImage_shader(struct gl_context * ctx,
       return false;
 
    view_target = get_target_from_texture(src);
-   /* I don't know why this works
-    * only for the texture rects
-    * but that's how it is
-    */
-   if ((src->target != PIPE_TEXTURE_RECT &&
+
+   /* 64K x 64K aren't supported by the shader (pbo_data::width/height have 16 bits) */
+   if (width >= UINT16_MAX || height >= UINT16_MAX ||
+       /* I don't know why this works only for the texture rects
+        * but that's how it is. */
+       (src->target != PIPE_TEXTURE_RECT &&
        /* this would need multiple samplerviews */
        ((util_format_is_depth_and_stencil(src_format) && util_format_is_depth_and_stencil(dst_format)) ||
        /* these format just doesn't work and science can't explain why */