Fix resolver for fields uses in constructors.

dart/frog/tests/leg/src/ResolverTest.dart

 // Copyright (c) 2011, 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.
 
 #import("../../../leg/leg.dart");
 #import("../../../leg/elements/elements.dart");
 #import("../../../leg/tree/tree.dart");
 #import("../../../leg/util/util.dart");
 #import("mock_compiler.dart");
 #import("parser_helper.dart");
@@ skipping 416 matching lines @@
 resolveConstructor(String script, String statement, String className,
                    String constructor, int expectedElementCount,
                    [List expectedWarnings = const [],
                    List expectedErrors = const []]) {
   MockCompiler compiler = new MockCompiler();
   compiler.parseScript(script);
   compiler.resolveStatement(statement);
   ClassElement classElement =
       compiler.universe.find(buildSourceString(className));
   Element element =
-      classElement.lookupLocalElement(buildSourceString(constructor));
+      classElement.lookupConstructor(buildSourceString(constructor));
   FunctionExpression tree = element.parseNode(compiler, compiler);
   ResolverVisitor visitor = new FullResolverVisitor(compiler, element);
   compiler.resolver.resolveInitializers(element, tree, visitor);
   Expect.equals(expectedElementCount, visitor.mapping.map.length);
 
   compareWarningKinds(script, expectedWarnings, compiler.warnings);
   compareWarningKinds(script, expectedErrors, compiler.errors);
 }
 
 testInitializers() {
@@ skipping 30 matching lines @@
                 int bar;
                 A() : this.foo = bar;
               }""";
   resolveConstructor(script, "A a = new A();", "A", "A", 2,
                      [], [MessageKind.NOT_STATIC]);
 }
 
 length(Link link) => link.isEmpty() ? 0 : length(link.tail) + 1;
 
 at(Link link, int index) => (index == 0) ? link.head : at(link.tail, index - 1);