Split World usage into open, inference, and closed world.

tests/compiler/dart2js/exit_code_test.dart

 // Copyright (c) 2013, 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.
 
 // Test the exit code of dart2js in case of exceptions, errors, warnings, etc.
 
 
 import 'dart:async';
 import 'dart:io' show Platform;
 
@@ skipping 139 matching lines @@
 }
 
 class TestResolver extends ResolverTask {
   final TestCompiler compiler;
 
   TestResolver(TestCompiler compiler, ConstantCompiler constantCompiler)
       : this.compiler = compiler,
         super(
             compiler.resolution,
             constantCompiler,
-            compiler.world,
+            compiler.openWorld,
             compiler.measurer);
 
   void computeClassMembers(ClassElement element) {
     compiler.test('ResolverTask.computeClassMembers');
     super.computeClassMembers(element);
   }
 }
 
 int checkedResults = 0;
 
@@ skipping 116 matching lines @@
 
       expected = _expectedExitCode(
           beforeRun: tests[marker], fatalWarnings: true);
       totalExpectedErrors += expected.length;
       await testExitCodes(marker, expected, ['--fatal-warnings']);
     }
 
     Expect.equals(totalExpectedErrors, checkedResults);
   });
 }