Preprocess structured stack trace on GC to get rid of code reference.

src/messages.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // -------------------------------------------------------------------
 
 var $errorToString;
 var $formatMessage;
 var $getStackTraceLine;
 var $messageGetPositionInLine;
@@ skipping 991 matching lines @@
 
 
 function GetStackFrames(raw_stack) {
   var frames = new InternalArray();
   var sloppy_frames = raw_stack[0];
   for (var i = 1; i < raw_stack.length; i += 4) {
     var recv = raw_stack[i];
     var fun = raw_stack[i + 1];
     var code = raw_stack[i + 2];
     var pc = raw_stack[i + 3];
-    var pos = %FunctionGetPositionForOffset(code, pc);
+    var pos = %_IsSmi(code) ? code : %FunctionGetPositionForOffset(code, pc);
     sloppy_frames--;
     frames.push(new CallSite(recv, fun, pos, (sloppy_frames < 0)));
   }
   return frames;
 }
 
 
 // Flag to prevent recursive call of Error.prepareStackTrace.
 var formatting_custom_stack_trace = false;
 
@@ skipping 281 matching lines @@
   return MakeGenericError(GlobalTypeError, type, [arg]);
 }
 
 //Boilerplate for exceptions for stack overflows. Used from
 //Isolate::StackOverflow().
 $stackOverflowBoilerplate = MakeRangeError(kStackOverflow);
 %DefineAccessorPropertyUnchecked($stackOverflowBoilerplate, 'stack',
                                  StackTraceGetter, StackTraceSetter, DONT_ENUM);
 
 })();