Takes the script offset into account when obtaining the column of the message.

src/messages.js

Index: src/messages.js
diff --git a/src/messages.js b/src/messages.js
index cd4664ee2639ba5e4e4cf2ea9ddd7fe74af796e7..63cefc877d695ef2d33a98621efd3c5fc6c92506 100644
--- a/src/messages.js
+++ b/src/messages.js
@@ -542,7 +542,7 @@ utils.SetUpLockedPrototype(SourceSlice,
 function GetPositionInLine(message) {
   var script = %MessageGetScript(message);
   var start_position = %MessageGetStartPosition(message);
-  var location = script.locationFromPosition(start_position, false);
+  var location = script.locationFromPosition(start_position, true);
   if (location == null) return -1;
   return location.column;
 }