Fix x64 build.

src/x64/virtual-frame-x64.h

Index: src/x64/virtual-frame-x64.h
===================================================================
--- src/x64/virtual-frame-x64.h	(revision 1950)
+++ src/x64/virtual-frame-x64.h	(working copy)
@@ -485,18 +485,6 @@
 
   bool Equals(VirtualFrame* other);
 
-  // Perform initialization required during entry frame computation
-  // after setting the virtual frame element at index in frame to be
-  // target.
-  void InitializeEntryElement(int index, FrameElement* target) {
-    elements_[index].clear_copied();
-    if (target->is_register()) {
-      register_locations_[target->reg().code()] = index;
-    } else if (target->is_copy()) {
-      elements_[target->index()].set_copied();
-    }
-  }
-
   friend class JumpTarget;
 };