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

runtime/vm/stack_frame_arm.cc

Index: runtime/vm/stack_frame_arm.cc
===================================================================
--- runtime/vm/stack_frame_arm.cc	(revision 18203)
+++ runtime/vm/stack_frame_arm.cc	(working copy)
@@ -27,12 +27,18 @@
 }
 
 
-intptr_t EntryFrame::ExitLinkOffset() {
+intptr_t EntryFrame::ExitLinkOffset() const {
   UNIMPLEMENTED();
   return 0;
 }
 
 
+intptr_t EntryFrame::SavedContextOffset() const {
+  UNIMPLEMENTED();
+  return 0;
+}
+
+
 void StackFrameIterator::SetupLastExitFrameData() {
   UNIMPLEMENTED();
 }