simplify constructors, fixes #564

test/codegen/expect/BenchmarkBase.js

 dart_library.library('BenchmarkBase', null, /* Imports */[
   'dart_sdk'
 ], function(exports, dart_sdk) {
   'use strict';
   const core = dart_sdk.core;
   const dart = dart_sdk.dart;
   const dartx = dart_sdk.dartx;
   const BenchmarkBase$ = Object.create(null);
   BenchmarkBase$.Expect = class Expect extends core.Object {
     static equals(expected, actual) {
@@ skipping 15 matching lines @@
   };
   dart.setSignature(BenchmarkBase$.Expect, {
     methods: () => ({fail: [dart.dynamic, [dart.dynamic]]}),
     statics: () => ({
       equals: [dart.void, [dart.dynamic, dart.dynamic]],
       listEquals: [dart.void, [core.List, core.List]]
     }),
     names: ['equals', 'listEquals']
   });
   BenchmarkBase$.BenchmarkBase = class BenchmarkBase extends core.Object {
-    BenchmarkBase(name) {
+    new(name) {
       this.name = name;
     }
     run() {}
     warmup() {
       this.run();
     }
     exercise() {
       for (let i = 0; i < 10; i++) {
         this.run();
       }
@@ skipping 23 matching lines @@
       }), 2000);
       this.teardown();
       return result;
     }
     report() {
       let score = this.measure();
       core.print(`${this.name}(RunTime): ${score} us.`);
     }
   };
   dart.setSignature(BenchmarkBase$.BenchmarkBase, {
-    constructors: () => ({BenchmarkBase: [BenchmarkBase$.BenchmarkBase, [core.String]]}),
+    constructors: () => ({new: [BenchmarkBase$.BenchmarkBase, [core.String]]}),
     methods: () => ({
       run: [dart.void, []],
       warmup: [dart.void, []],
       exercise: [dart.void, []],
       setup: [dart.void, []],
       teardown: [dart.void, []],
       measure: [core.double, []],
       report: [dart.void, []]
     }),
     statics: () => ({measureFor: [core.double, [core.Function, core.int]]}),
     names: ['measureFor']
   });
   // Exports:
   exports.BenchmarkBase = BenchmarkBase$;
 });