Add support for accessing field formal parameters in the initializer list of constructors

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

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer.src.dart.resolver.scope;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 95 matching lines @@
     }
     List<MethodElement> methods = classElement.methods;
     int methodLength = methods.length;
     for (int i = 0; i < methodLength; i++) {
       define(methods[i]);
     }
   }
 }
 
 /**
+ * The scope defined for the initializers in a constructor.
+ */
+class ConstructorInitializerScope extends EnclosedScope {
+  /**
+   * Initialize a newly created scope, enclosed within the [enclosingScope].
+   */
+  ConstructorInitializerScope(Scope enclosingScope, ConstructorElement element)
+      : super(enclosingScope) {
+    _initializeFieldFormalParameters(element);
+  }
+
+  /**
+   * Initialize the local scope with all of the field formal parameters.
+   */
+  void _initializeFieldFormalParameters(ConstructorElement element) {
+    for (ParameterElement parameter in element.parameters) {
+      if (parameter is FieldFormalParameterElement) {
+        define(parameter);
+      }
+    }
+  }
+}
+
+/**
  * A scope that is lexically enclosed in another scope.
  */
 class EnclosedScope extends Scope {
   /**
    * The scope in which this scope is lexically enclosed.
    */
   @override
   final Scope enclosingScope;
 
   /**
@@ skipping 1019 matching lines @@
 
   /**
    * Define the type parameters declared by the [classElement].
    */
   void _defineTypeParameters(ClassElement classElement) {
     for (TypeParameterElement typeParameter in classElement.typeParameters) {
       define(typeParameter);
     }
   }
 }