Merge of source position information from kernel-sdk.

runtime/vm/exceptions.cc

Index: runtime/vm/exceptions.cc
diff --git a/runtime/vm/exceptions.cc b/runtime/vm/exceptions.cc
index 4b73efd02026d37a0fefc1ab894238631bf9667d..212094db8e9b03e3126735f63d6bc889f702b397 100644
--- a/runtime/vm/exceptions.cc
+++ b/runtime/vm/exceptions.cc
@@ -511,12 +511,11 @@ void Exceptions::CreateAndThrowTypeError(TokenPosition location,
 
   DartFrameIterator iterator;
   const Script& script = Script::Handle(zone, GetCallerScript(&iterator));
-  intptr_t line;
+  intptr_t line = -1;
   intptr_t column = -1;
-  if (script.HasSource()) {
+  ASSERT(!script.IsNull());
+  if (location.IsReal()) {
     script.GetTokenLocation(location, &line, &column);
-  } else {
-    script.GetTokenLocation(location, &line, NULL);
   }
   // Initialize '_url', '_line', and '_column' arguments.
   args.SetAt(0, String::Handle(zone, script.url()));