Change VirtualFrame::AdjustCopies to mark target as invalid.

src/virtual-frame-arm.cc

Index: src/virtual-frame-arm.cc
===================================================================
--- src/virtual-frame-arm.cc	(revision 1574)
+++ src/virtual-frame-arm.cc	(working copy)
@@ -290,14 +290,9 @@
 }
 
 
-// Before changing an element which is copied, adjust so that the
-// first copy becomes the new backing store and all the other copies
-// are updated.  If the original was in memory, the new backing store
-// is allocated to a register.  Return a copy of the new backing store
-// or an invalid element if the original was not a copy.
-FrameElement VirtualFrame::AdjustCopies(int index) {
+int VirtualFrame::InvalidateFrameSlotAt(int index) {
   UNIMPLEMENTED();
-  return FrameElement::InvalidElement();
+  return kIllegalIndex;
 }