Fix for issues 6080 - pass in the Isolate's top context into the stub for invoking dart code from n…

runtime/vm/scopes.cc

Index: runtime/vm/scopes.cc
===================================================================
--- runtime/vm/scopes.cc	(revision 18232)
+++ runtime/vm/scopes.cc	(working copy)
@@ -259,7 +259,7 @@
         desc.info.index = var->index();
         vars->Add(desc);
       } else if (var->name().Equals(
-            Symbols::Name(Symbols::kSavedEntryContextVarId))) {
+            Symbols::Name(Symbols::kSavedCurrentContextVarId))) {
         // This is the local variable in which the function saves the
         // caller's chain of closure contexts (caller's CTX register).
         VarDesc desc;