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

runtime/vm/stack_frame_ia32.cc

Index: runtime/vm/stack_frame_ia32.cc
===================================================================
--- runtime/vm/stack_frame_ia32.cc	(revision 18203)
+++ runtime/vm/stack_frame_ia32.cc	(working copy)
@@ -13,6 +13,7 @@
 
 // The constant kExitLinkOffsetInEntryFrame must be kept in sync with the
 // code in the InvokeDartCode stub.
+static const int kSavedContextOffsetInEntryFrame = -5 * kWordSize;
 static const int kExitLinkOffsetInEntryFrame = -4 * kWordSize;
 static const int kPcAddressOffsetFromSp = -1 * kWordSize;
 static const int kSpOffsetFromPreviousFp = 2 * kWordSize;
@@ -33,11 +34,16 @@
 }
 
 
-intptr_t EntryFrame::ExitLinkOffset() {
+intptr_t EntryFrame::ExitLinkOffset() const {
   return kExitLinkOffsetInEntryFrame;
 }
 
 
+intptr_t EntryFrame::SavedContextOffset() const {
+  return kSavedContextOffsetInEntryFrame;
+}
+
+
 void StackFrameIterator::SetupLastExitFrameData() {
   Isolate* current = Isolate::Current();
   uword exit_marker = current->top_exit_frame_info();