Fix regression in TypedefMirror.owner introduced when making ClassMirror.owner lazy.

tests/lib/mirrors/mirrors_test.dart

Index: tests/lib/mirrors/mirrors_test.dart
===================================================================
--- tests/lib/mirrors/mirrors_test.dart	(revision 25237)
+++ tests/lib/mirrors/mirrors_test.dart	(working copy)
@@ -254,6 +254,11 @@
     expect(typedefMirror.simpleName, equals(const Symbol('Typedef')));
     expect(typedefMirror.qualifiedName,
            equals(const Symbol('MirrorsTest.Typedef')));
+
+    var typedefMirrorDeNovo = reflectClass(Typedef);
+    expect(typedefMirrorDeNovo.simpleName, equals(const Symbol('Typedef')));
+    expect(typedefMirrorDeNovo.qualifiedName,
+           equals(const Symbol('MirrorsTest.Typedef')));
   }
 
   expect(methodMirror.simpleName, equals(const Symbol('testNames')));