Change gate logic for mgca_type_const_syntax to work also if min_generic_const_args is enabled.

Author: Keith-Cancel

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -532,7 +532,6 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session, features: &Features) {
     gate_all!(fn_delegation, "functions delegation is not yet fully implemented");
     gate_all!(postfix_match, "postfix match is experimental");
     gate_all!(mut_ref, "mutable by-reference bindings are experimental");
-    gate_all!(mgca_type_const_syntax, "`type const` syntax is experimental");
     gate_all!(min_generic_const_args, "unbraced const blocks as const args are experimental");
     // associated_const_equality is stabilized as part of min_generic_const_args
     if let Some(spans) = spans.get(&sym::associated_const_equality) {
@@ -550,6 +549,27 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session, features: &Features) {
             }
         }
     }
+    // `mgca_type_const_syntax` is part of `min_generic_const_args` so either
+    // or both are enabled we don't need to emit a feature error.
+    if let Some(spans) = spans.get(&sym::mgca_type_const_syntax) {
+        for span in spans {
+            if visitor.features.min_generic_const_args()
+                || visitor.features.mgca_type_const_syntax()
+                || span.allows_unstable(sym::min_generic_const_args)
+                || span.allows_unstable(sym::mgca_type_const_syntax)
+            {
+                continue;
+            }
+            feature_err(
+                &visitor.sess,
+                sym::mgca_type_const_syntax,
+                *span,
+                "`type const` syntax is experimental",
+            )
+            .emit();
+        }
+    }
+
     gate_all!(global_registration, "global registration is experimental");
     gate_all!(return_type_notation, "return type notation is experimental");
     gate_all!(pin_ergonomics, "pinned reference syntax is experimental");