Implement DeclarationMirror.location for all but ParameterMirrors.

tests/lib/mirrors/class_mirror_location_other.dart

Index: tests/lib/mirrors/class_mirror_location_other.dart
diff --git a/tests/language/regress_21998_lib2.dart b/tests/lib/mirrors/class_mirror_location_other.dart
similarity index 63%
copy from tests/language/regress_21998_lib2.dart
copy to tests/lib/mirrors/class_mirror_location_other.dart
index 8d1ac8934162980fe9353119e7b035bc27e59a09..eb94d21d6ce68ee04f4dfd525708b60708426d63 100644
--- a/tests/language/regress_21998_lib2.dart
+++ b/tests/lib/mirrors/class_mirror_location_other.dart
@@ -2,8 +2,10 @@
 // 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.
 
-library regress_21998_lib2;
+part of test.class_location;
 
-import 'dart:math';
+class ClassInOtherFile {}
 
-lib2_max(a, b) => max(a, b);
+  class SpaceIndentedInOtherFile {}
+
+	class TabIndentedInOtherFile {}