Adds C++ API for retrieving a stack trace without running JavaScript

src/messages.js

 // Copyright 2006-2008 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 24 matching lines @@
 
 // Matches Script::CompilationType from objects.h
 var COMPILATION_TYPE_HOST = 0;
 var COMPILATION_TYPE_EVAL = 1;
 var COMPILATION_TYPE_JSON = 2;
 
 // Lazily initialized.
 var kVowelSounds = 0;
 var kCapitalVowelSounds = 0;
 
+// Matches Messages::kNoLineNumberInfo from v8.h
+var kNoLineNumberInfo = 0;
+
 // If this object gets passed to an error constructor the error will
 // get an accessor for .message that constructs a descriptive error
 // message on access.
 var kAddMessageAccessorsMarker = { };
 
 
 function GetInstanceName(cons) {
   if (cons.length == 0) {
     return "";
   }
@@ skipping 141 matching lines @@
       illegal_access:               "illegal access"
     };
   }
   var format = kMessages[message.type];
   if (!format) return "<unknown message " + message.type + ">";
   return FormatString(format, message.args);
 }
 
 
 function GetLineNumber(message) {
-  if (message.startPos == -1) return -1;
+  if (message.startPos == -1) return kNoLineNumberInfo;
   var location = message.script.locationFromPosition(message.startPos, true);
-  if (location == null) return -1;
+  if (location == null) return kNoLineNumberInfo;
   return location.line + 1;
 }
 
 
 // Returns the source code line containing the given source
 // position, or the empty string if the position is invalid.
 function GetSourceLine(message) {
   var location = message.script.locationFromPosition(message.startPos, true);
   if (location == null) return "";
   location.restrict();
@@ skipping 746 matching lines @@
     return this.name + ": " + FormatMessage({ type: type, args: this.arguments });
   }
   var message = this.message;
   return this.name + (message ? (": " + message) : "");
 }, DONT_ENUM);
 
 
 // Boilerplate for exceptions for stack overflows. Used from
 // Top::StackOverflow().
 const kStackOverflowBoilerplate = MakeRangeError('stack_overflow', []);