Skip stack trace formatting in case the global object is already dead.

test/mjsunit/stack-traces-overflow.js

 // Copyright 2012 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 39 matching lines @@
 
 // Test getter to make sure setter does not affect the boilerplate.
 try {
   rec1(0);
 } catch (e) {
   assertTrue(e.stack.indexOf("rec1") > 0);
   assertInstanceof(e, RangeError);
 }
 
 
+function assertStackAccessors(error_object, type) {
+  assertSame(type,
+             typeof Object.getOwnPropertyDescriptor(error_object, "stack").get);
+  assertSame(type,
+             typeof Object.getOwnPropertyDescriptor(error_object, "stack").set);
+}
+
 // Check setting/getting stack property on the prototype chain.
 function testErrorPrototype(prototype) {
   var object = {};
   object.__proto__ = prototype;
   object.stack = "123";
   assertEquals("123", object.stack);
   assertTrue("123" != prototype.stack);
+  // Check that the accessors on the prototype error object are untouched.
+  assertStackAccessors(prototype, "function");
+  assertEquals("123", Object.getOwnPropertyDescriptor(object, "stack").value);
+  prototype.stack = "abc";
+  assertStackAccessors(prototype, "undefined");
 }
 
 try {
   rec1(0);
 } catch (e) {
   e.stack;
   testErrorPrototype(e);
 }
 
 try {
@@ skipping 36 matching lines @@
   assertEquals(undefined, e.stack);
 }
 
 Error.stackTraceLimit = 3;
 Error = "";  // Overwrite Error in the global object.
 try {
   rec1(0);
 } catch (e) {
   assertEquals(4, e.stack.split('\n').length);
 }