Change signature of lookupConstructor to only require a name.

pkg/compiler/lib/src/ssa/builder.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.
 
 part of ssa;
 
 class SsaFunctionCompiler implements FunctionCompiler {
   SsaCodeGeneratorTask generator;
   SsaBuilderTask builder;
   SsaOptimizerTask optimizer;
@@ skipping 1860 matching lines @@
     }
 
     if (!foundSuperOrRedirect) {
       // No super initializer found. Try to find the default constructor if
       // the class is not Object.
       ClassElement enclosingClass = constructor.enclosingClass;
       ClassElement superClass = enclosingClass.superclass;
       if (!enclosingClass.isObject) {
         assert(superClass != null);
         assert(superClass.resolutionState == STATE_DONE);
-        Selector selector =
-            new Selector.callDefaultConstructor(enclosingClass.library);
         // TODO(johnniwinther): Should we find injected constructors as well?
-        FunctionElement target = superClass.lookupConstructor(selector);
+        FunctionElement target = superClass.lookupDefaultConstructor();
         if (target == null) {
           compiler.internalError(superClass,
               "No default constructor available.");
         }
+        Selector selector =
+                    new Selector.callDefaultConstructor(enclosingClass.library);
         List<HInstruction> arguments =
             selector.makeArgumentsList2(const Link<ast.Node>(),
                                         target.implementation,
                                         null,
                                         handleConstantForOptionalParameter);
         inlineSuperOrRedirect(target,
                               arguments,
                               constructors,
                               fieldValues,
                               constructor);
@@ skipping 4724 matching lines @@
     if (unaliased is TypedefType) throw 'unable to unalias $type';
     unaliased.accept(this, builder);
   }
 
   void visitDynamicType(DynamicType type, SsaBuilder builder) {
     JavaScriptBackend backend = builder.compiler.backend;
     ClassElement cls = backend.findHelper('DynamicRuntimeType');
     builder.push(new HDynamicType(type, new TypeMask.exact(cls, classWorld)));
   }
 }