Make super-formal parameters visible only in the initializers scope.

Bug: dart-lang/language#2056 (comment)
Change-Id: I155c576f28f1f0ff851772723e7bd01ff062f651
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/227901
Reviewed-by: Phil Quitslund <[email protected]>
Reviewed-by: Samuel Rawlins <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

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

@@ -83,7 +83,8 @@ class FormalParameterScope extends EnclosedScope {
     List<ParameterElement> elements,
   ) : super(parent) {
     for (var parameter in elements) {
-      if (parameter is! FieldFormalParameterElement) {
+      if (parameter is! FieldFormalParameterElement &&
+          parameter is! SuperFormalParameterElement) {
         _addGetter(parameter);
       }
     }

pkg/analyzer/test/src/dart/resolution/super_formal_parameter_test.dart

@@ -130,4 +130,42 @@ class B extends A {
       findElement.unnamedConstructor('B').superFormalParameter('a'),
     );
   }
+
+  test_scoping_inBody() async {
+    await assertNoErrorsInCode(r'''
+class A {
+  final int a;
+  A(this.a);
+}
+
+class B extends A {
+  B(super.a) {
+    a; // ref
+  }
+}
+''');
+
+    assertElement(
+      findNode.simple('a; // ref'),
+      findElement.getter('a', of: 'A'),
+    );
+  }
+
+  test_scoping_inInitializer() async {
+    await assertNoErrorsInCode(r'''
+class A {
+  A(int a);
+}
+
+class B extends A {
+  var f;
+  B(super.a) : f = ((){ a; });
+}
+''');
+
+    assertElement(
+      findNode.simple('a; }'),
+      findElement.unnamedConstructor('B').superFormalParameter('a'),
+    );
+  }
 }