fix language_tests.js to use strict mode

test/codegen/language/async_throw_in_catch_test.dart

Index: test/codegen/language/async_throw_in_catch_test.dart
diff --git a/test/codegen/language/async_throw_in_catch_test.dart b/test/codegen/language/async_throw_in_catch_test.dart
index 6117a2605792ed195bfe395426c34dd8cf442d4d..e529e8f59998a1f3eed5636e2c9a0d3138019289 100644
--- a/test/codegen/language/async_throw_in_catch_test.dart
+++ b/test/codegen/language/async_throw_in_catch_test.dart
@@ -15,7 +15,7 @@ class Tracer {
 
   void trace(msg) {
     if (name != null) {
-      print("Tracing $name: $msg");
+      //print("Tracing $name: $msg");

[vsm, 2015/08/03 20:57:33]

Maybe a comment here?   Hmm - ideally we'd have a tracing function that only
prints if the test fails.

[Jennifer Messerly, 2015/08/03 21:08:11]

Done.

     }
     Expect.equals(expected[counter], msg);
     counter++;