Be less aggressive in sharing contexts between scopes so that sibling contexts

tests/language/regress_22858_test.dart

+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+import 'package:expect/expect.dart';
+
+main() {
+    var good = "good";
+
+    f1() {
+      {
+        var bad = "bad";
+        f2() { bad; }
+      }
+
+      Expect.equals("good", good);
+      do {
+        Expect.equals("good", good);
+        int ugly = 0;
+        f3() { ugly; }
+      } while (false);
+    }
+
+    f1();

[srdjan, 2015/03/19 22:34:44]

Indent 2 spaces

[regis, 2015/03/19 22:38:53]

Done.

+}