Make dart2js unittests async.

tests/compiler/dart2js/minify_many_locals_test.dart

Index: tests/compiler/dart2js/minify_many_locals_test.dart
diff --git a/tests/compiler/dart2js/minify_many_locals_test.dart b/tests/compiler/dart2js/minify_many_locals_test.dart
index 1d62fa432f5a96171adc131afcfde434192b74f8..7ab6f2f29487d9595fb43714259199cef7f76d57 100644
--- a/tests/compiler/dart2js/minify_many_locals_test.dart
+++ b/tests/compiler/dart2js/minify_many_locals_test.dart
@@ -3,7 +3,8 @@
 // BSD-style license that can be found in the LICENSE file.
 // Test that parameters keep their names in the output.
 
-import "package:expect/expect.dart";
+import 'package:async_helper/async_helper.dart';
+import 'package:expect/expect.dart';
 import 'compiler_helper.dart';
 
 main() {
@@ -17,25 +18,29 @@ main() {
     buffer.write("x$i+");
   }
   buffer.write("2000; return i; }");
-  var generated = compile(buffer.toString(), entry: 'foo', minify: true);
-  RegExp re = new RegExp(r"\(a,b,c");
-  Expect.isTrue(re.hasMatch(generated));
+  String code = buffer.toString();
 
-  re = new RegExp(r"x,y,z,a0,a1,a2");
-  Expect.isTrue(re.hasMatch(generated));
+  asyncTest(() => compile(code, entry: 'foo', minify: true)
+      .then((String generated) {
+    RegExp re = new RegExp(r"\(a,b,c");
+    Expect.isTrue(re.hasMatch(generated));
 
-  re = new RegExp(r"y,z,a0,a1,a2,a3,a4,a5,a6");
-  Expect.isTrue(re.hasMatch(generated));
+    re = new RegExp(r"x,y,z,a0,a1,a2");
+    Expect.isTrue(re.hasMatch(generated));
 
-  re = new RegExp(r"g8,g9,h0,h1");
-  Expect.isTrue(re.hasMatch(generated));
+    re = new RegExp(r"y,z,a0,a1,a2,a3,a4,a5,a6");
+    Expect.isTrue(re.hasMatch(generated));
 
-  re = new RegExp(r"z8,z9,aa0,aa1,aa2");
-  Expect.isTrue(re.hasMatch(generated));
+    re = new RegExp(r"g8,g9,h0,h1");
+    Expect.isTrue(re.hasMatch(generated));
 
-  re = new RegExp(r"aa9,ab0,ab1");
-  Expect.isTrue(re.hasMatch(generated));
+    re = new RegExp(r"z8,z9,aa0,aa1,aa2");
+    Expect.isTrue(re.hasMatch(generated));
 
-  re = new RegExp(r"az9,ba0,ba1");
-  Expect.isTrue(re.hasMatch(generated));
+    re = new RegExp(r"aa9,ab0,ab1");
+    Expect.isTrue(re.hasMatch(generated));
+
+    re = new RegExp(r"az9,ba0,ba1");
+    Expect.isTrue(re.hasMatch(generated));
+  }));
 }