Follow up to fix v8::Exception::GetMessage() actually do what it was intended to.

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index 7e50929ebca31e56698f660b15ea791d5b81924b..35516320530849a2c14b2b72a7986d7b74912517 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -801,7 +801,7 @@ class Isolate {
   // Attempts to compute the current source location, storing the
   // result in the target out parameter.
   void ComputeLocation(MessageLocation* target);
-  void ComputeLocationFromStackTrace(MessageLocation* target,
+  bool ComputeLocationFromStackTrace(MessageLocation* target,
                                      Handle<Object> exception);
 
   Handle<JSMessageObject> CreateMessage(Handle<Object> exception,