Lazy call to custom stack trace formatting using Error.prepareStackTrace.

test/mjsunit/stack-traces.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 297 matching lines @@
 error = new Error({ toString: function() { fired = true; } });
 assertTrue(fired);
 error.stack;
 assertTrue(fired);
 
 // Check that throwing exception in a custom stack trace formatting function
 // does not lead to recursion.
 Error.prepareStackTrace = function() { throw new Error("abc"); };
 var message;
 try {
-  throw new Error();
+  try {
+    throw new Error();
+  } catch (e) {
+    e.stack;
+  }
 } catch (e) {
   message = e.message;
 }
 
 assertEquals("abc", message);
 
 // Test that modifying Error.prepareStackTrace by itself works.
 Error.prepareStackTrace = function() { Error.prepareStackTrace = "custom"; };
-new Error();
+new Error().stack;
 
 assertEquals("custom", Error.prepareStackTrace);