dart2js: set effective target for patched constructors

pkg/compiler/lib/src/elements/elements.dart

 // Copyright (c) 2012, 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 elements;
 
 import '../common.dart';
 import '../common/resolution.dart' show
     Resolution;
 import '../compiler.dart' show
@@ skipping 1266 matching lines @@
   ///     class E = C with D;
   ///
   /// Class `E` has a synthesized constructor, `E.c`, whose defining constructor
   /// is `C.c`.
   ConstructorElement get definingConstructor;
 
   /// The constant constructor defining the binding of fields if `const`,
   /// `null` otherwise.
   ConstantConstructor get constantConstructor;
 
-  /// `true` if this constructor is either `bool.fromEnviroment`
+  /// `true` if this constructor is one of `bool.fromEnvironment`,
+  /// `int.fromEnvironment`, or `String.fromEnvironment`.
   bool get isFromEnvironmentConstructor;
 
   /// Use [enclosingClass] instead.
   @deprecated
   get enclosingElement;
 }
 
 /// JavaScript backend specific element for the body of constructor.
 // TODO(johnniwinther): Remove this class from the element model.
 abstract class ConstructorBodyElement extends MethodElement {
@@ skipping 404 matching lines @@
   bool get isDeclaredByField;
 
   /// Returns `true` if this member is abstract.
   bool get isAbstract;
 
   /// If abstract, [implementation] points to the overridden concrete member,
   /// if any. Otherwise [implementation] points to the member itself.
   Member get implementation;
 }