[wildcards] fix constructor parameter initializer scope

See: #55680

Fixes:

MissingCompileTimeError -> Pass (expected Pass)
co19/LanguageFeatures/Wildcards/binding_A01_t02
co19/LanguageFeatures/Wildcards/initializing_formals_A02_t01
co19/LanguageFeatures/Wildcards/initializing_formals_A02_t03

MissingCompileTimeError -> Pass (expected Pass)
language/wildcard_variables/initializing_formal_parameters/this_initializer_access_error_test

Change-Id: I7c14757e312e7f426290ed63ed745eac4856bab3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/380160
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Phil Quitslund <[email protected]>

Author: pq

pkg/analyzer/lib/src/dart/element/scope.dart

@@ -14,7 +14,12 @@ import 'package:analyzer/src/utilities/extensions/collection.dart';
 /// The scope for the initializers in a constructor.
 class ConstructorInitializerScope extends EnclosedScope {
   ConstructorInitializerScope(super.parent, ConstructorElement element) {
-    element.parameters.forEach(_addGetter);
+    var wildcardsEnabled = element.library.hasWildcardVariablesFeatureEnabled;
+    for (var parameter in element.parameters) {
+      if (!(wildcardsEnabled && parameter.name == '_')) {
+        _addGetter(parameter);
+      }
+    }
   }
 }
 

pkg/analyzer/test/src/diagnostics/implicit_this_reference_in_initializer_test.dart

@@ -108,6 +108,30 @@ class A {
     ]);
   }
 
+  test_constructorInitializer_field_shadowingWildcard() async {
+    await assertErrorsInCode(r'''
+class A {
+  var v;
+  var _;
+  A(var _) : v = _;
+}
+''', [
+      error(CompileTimeErrorCode.IMPLICIT_THIS_REFERENCE_IN_INITIALIZER, 45, 1),
+    ]);
+  }
+
+  test_constructorInitializer_fieldFormalWildcard() async {
+    await assertErrorsInCode(r'''
+class C {
+  var _;
+  var f;
+  C(this._) : f = _;
+}
+''', [
+      error(CompileTimeErrorCode.IMPLICIT_THIS_REFERENCE_IN_INITIALIZER, 46, 1),
+    ]);
+  }
+
   test_constructorName() async {
     await assertNoErrorsInCode(r'''
 class A {