First pass at asynchronous input loading in dart2js.

tests/compiler/dart2js/dead_bailout_target_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.
 
 // This unit test of dart2js checks that a SSA bailout target
 // instruction gets removed from the graph when it's not used.
 
 import "package:expect/expect.dart";
+import "../../async_helper.dart";
 import 'compiler_helper.dart';
 
 String TEST = r'''
 main() {
   foo(1);
   foo([]);
 }
 
 class A {
   operator -() => this;
 }
 
 foo(a) {
   new A(); // Force having another operator-
   // Make the method recursive to always enable bailouts
   // and force a list instantiation.
   foo([]);
   // Force bailout on [a].
   for (int i = 0; i < 100; i++) a[0] = 42;
   // Force bailout on [:a.length:].
   for (int i = 0; i < 200; i++) a[0] = -a.length;
 }
 ''';
 
 main() {
   String generated = compile(TEST, entry: 'foo');
-
   // Check that we only have one bailout call. The second bailout call
   // is dead code because we know [:a.length:] is an int.
   checkNumberOfMatches(new RegExp('bailout').allMatches(generated).iterator, 1);
 
   // Check that the foo method does not have any call to
   // 'getInterceptor'. The environment for the second bailout contains
   // the interceptor of [:a.length:], but since the bailout is
   // removed, the interceptor is removed too.
   if (generated.contains(r'getInterceptor(a).$is')) {
     // If we have an interceptor for a type check, it should be the only one.
     checkNumberOfMatches(
         new RegExp('getInterceptor').allMatches(generated).iterator, 1);
   } else {
     Expect.isTrue(!generated.contains('getInterceptor'));
   }
 
-  generated = compileAll(TEST);
-  
-  // Check that the foo bailout method is generated.
-  checkNumberOfMatches(
-      new RegExp('foo\\\$bailout').allMatches(generated).iterator, 2);
+  asyncTest(() => compileAll(TEST).then((generated) {
+    // Check that the foo bailout method is generated.
+    checkNumberOfMatches(
+        new RegExp('foo\\\$bailout').allMatches(generated).iterator, 2);
 
-  // Check that it's the only bailout method.
-  checkNumberOfMatches(new RegExp('bailout').allMatches(generated).iterator, 2);
+    // Check that it's the only bailout method.
+    checkNumberOfMatches(new RegExp('bailout').allMatches(generated).iterator, 2);
 
-  // Check that the bailout method has a case 2 for the state, which
-  // is the second bailout in foo.
-  Expect.isTrue(generated.contains('case 2:'));
+    // Check that the bailout method has a case 2 for the state, which
+    // is the second bailout in foo.
+    Expect.isTrue(generated.contains('case 2:'));
 
-  // Finally, make sure that the reason foo does not contain
-  // 'getInterceptor' is not because the compiler renamed it.
-  Expect.isTrue(generated.contains('getInterceptor'));
+    // Finally, make sure that the reason foo does not contain
+    // 'getInterceptor' is not because the compiler renamed it.
+    Expect.isTrue(generated.contains('getInterceptor'));
+  }));
 }