Rollup merge of rust-lang#97999 - compiler-errors:type_changin_struct_update_is_probably_complete, r=oli-obk

Make `type_changing_struct_update` no longer an incomplete feature

After rust-lang#97705, I don't see what would make it incomplete anymore. `check_expr_struct_fields` seems to now implement the RFC to the letter.

r? ``````@nikomatsakis``````
cc ``````@rust-lang/types``````

Author: matthiaskrgr

compiler/rustc_feature/src/active.rs

@@ -521,7 +521,7 @@ declare_features! (
     (active, type_ascription, "1.6.0", Some(23416), None),
     /// Allows creation of instances of a struct by moving fields that have
     /// not changed from prior instances of the same struct (RFC #2528)
-    (incomplete, type_changing_struct_update, "1.58.0", Some(86555), None),
+    (active, type_changing_struct_update, "1.58.0", Some(86555), None),
     /// Allows unsized fn parameters.
     (active, unsized_fn_params, "1.49.0", Some(48055), None),
     /// Allows unsized rvalues at arguments and parameters.