When inlining, create a new local handler, to avoid polluting the local handler of the caller.

tests/language/inline_test.dart

+// Copyright (c) 2013, 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.
+
+// Regression test for dart2js that used to produce a non-valid SSA
+// graph when inlining within a loop.
+
+class X {
+  void x(a, b) {
+   do {
+     if (identical(a, b)) {
+       break;
+     }
+   } while (p(a, b));
+  }
+
+  bool p(a, b) {
+   return identical(a, b);
+  }
+}
+
+main() {
+  var x = new X();
+  x.x(1, 2);
+}