Add a test case for Phi representations

BUG=chromium:167394
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/18838002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15553 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/mjsunit/compiler/phi-representations.js

+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax
+
+function ar() {
+  var r = undefined;
+  var f = 1;
+  while (f--) {
+    r = (typeof r === 'undefined') ? 0.1 : r;
+  };
+  return (r - r);
+}
+
+assertEquals(0, ar());
+assertEquals(0, ar());
+%OptimizeFunctionOnNextCall(ar);
+assertEquals(0, ar());
+
+function ar2() {
+  var r = undefined;
+  var f = 1;
+  while (f--) {
+    r = r === undefined ? 0.1 : r;
+  };
+  return (r - r);
+}
+
+assertEquals(0, ar2());
+assertEquals(0, ar2());
+%OptimizeFunctionOnNextCall(ar2);
+assertEquals(0, ar2());