Fix issue 186:...

test/mjsunit/regress/regress-186.js

 // Copyright 2009 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
@@ skipping 15 matching lines @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Make sure that eval can introduce a local variable called __proto__.
 // See http://code.google.com/p/v8/issues/detail?id=186
 
 var setterCalled = false;
 
 var o = {};
 o.__defineSetter__("x", function() { setterCalled = true; });
 
+function runTest(test) {
+  setterCalled = false;
+  test();
+}
+
 function testLocal() {
   // Add property called __proto__ to the extension object.
   eval("var __proto__ = o");
   // Check that the extension object's prototype did not change.
   eval("var x = 27");
   assertFalse(setterCalled, "prototype of extension object changed");
+  assertEquals(o, eval("__proto__"));
+}
+
+function testConstLocal() {
+  // Add const property called __proto__ to the extension object.
+  eval("const __proto__ = o");
+  // Check that the extension object's prototype did not change.
+  eval("var x = 27");
+  assertFalse(setterCalled, "prototype of extension object changed");
+  assertEquals(o, eval("__proto__"));
 }
 
 function testGlobal() {
   // Assign to the global __proto__ property.
   eval("__proto__ = o");
   // Check that the prototype of the global object changed.
   eval("x = 27");
   assertTrue(setterCalled, "prototype of global object did not change");
   setterCalled = false;
+  assertEquals(o, eval("__proto__"));
 }
 
-testLocal();
-testGlobal();
+runTest(testLocal);
+runTest(testConstLocal);
+runTest(testGlobal);