nir/lower_double_ops: Rework the if (progress) tree

Fixes: d7d35a9522 "nir/lower_doubles: Use the new NIR lowering..."
Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5170>
(cherry picked from commit 111b0a6699)

.pick_status.json

@@ -1705,7 +1705,7 @@
         "description": "nir/lower_double_ops: Rework the if (progress) tree",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "master_sha": null,
         "because_sha": "d7d35a9522ea5b524732a8b730008d725b84abdf"
     },

src/compiler/nir/nir_lower_double_ops.c

@@ -736,7 +736,14 @@ nir_lower_doubles_impl(nir_function_impl *impl,
        * inlining.
        */
       nir_opt_deref_impl(impl);
-   }
+   } else if (progress) {
+      nir_metadata_preserve(impl, nir_metadata_block_index |
+                                  nir_metadata_dominance);
+    } else {
+#ifndef NDEBUG
+      impl->valid_metadata &= ~nir_metadata_not_properly_reset;
+#endif
+    }
 
    return progress;
 }