nir: Properly invalidate metadata in nir_opt_copy_prop().

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
Reviewed-by: Eduardo Lima Mitev <elima@igalia.com>
Cc: mesa-stable@lists.freedesktop.org
(cherry picked from commit 0f037bd71f)

src/glsl/nir/nir_opt_copy_propagate.c

@@ -262,6 +262,12 @@ nir_copy_prop_impl(nir_function_impl *impl)
    bool progress = false;
 
    nir_foreach_block(impl, copy_prop_block, &progress);
+
+   if (progress) {
+      nir_metadata_preserve(impl, nir_metadata_block_index |
+                                  nir_metadata_dominance);
+   }
+
    return progress;
 }