Wrap lazy compilation errors when parsing metadata. Addresses the poor error reporting in issue 120…

runtime/tests/vm/dart/isolate_mirror_local_test.dart

Index: runtime/tests/vm/dart/isolate_mirror_local_test.dart
===================================================================
--- runtime/tests/vm/dart/isolate_mirror_local_test.dart	(revision 25492)
+++ runtime/tests/vm/dart/isolate_mirror_local_test.dart	(working copy)
@@ -407,6 +407,7 @@
 class MyInterface {
 }
 
+@notDefined
 class MyClass extends MySuperClass implements MyInterface {
   MyClass(this.value) {}
   MyClass.named() {}
@@ -445,6 +446,7 @@
   Expect.equals(const Symbol('isolate_mirror_local_test'), cls.owner.simpleName);
   Expect.isTrue(cls.isClass);
   Expect.equals(const Symbol('MyInterface'), cls.superinterfaces[0].simpleName);
+  Expect.throws(() => cls.metadata, (e) => e is MirroredCompilationError, 'Bad metadata');

[ahe, 2013/07/26 10:13:03]

Long line.

   // TODO(ahe): toString() test disabled for now as Symbols are 100% opaque.
   // Expect.equals("ClassMirror on 'MyClass'", cls.toString());

[ahe, 2013/07/26 10:13:03]

I think you can enable this again.