Remove stack_frame_<arch>.cc files.

runtime/vm/stub_code_x64.cc

Index: runtime/vm/stub_code_x64.cc
===================================================================
--- runtime/vm/stub_code_x64.cc	(revision 22469)
+++ runtime/vm/stub_code_x64.cc	(working copy)
@@ -14,6 +14,7 @@
 #include "vm/object_store.h"
 #include "vm/resolver.h"
 #include "vm/scavenger.h"
+#include "vm/stack_frame.h"
 #include "vm/stub_code.h"
 
 
@@ -729,8 +730,9 @@
 
   // Save the top exit frame info. Use RAX as a temporary register.
   // StackFrameIterator reads the top exit frame info saved in this frame.
-  // The constant kExitLinkOffsetInEntryFrame must be kept in sync with the
-  // code below: kExitLinkOffsetInEntryFrame = -8 * kWordSize.
+  // The constant kExitLinkSlotFromEntryFp must be kept in sync with the
+  // code below.
+  ASSERT(kExitLinkSlotFromEntryFp == -8);
   __ movq(RAX, Address(R8, Isolate::top_exit_frame_info_offset()));
   __ pushq(RAX);
   __ movq(Address(R8, Isolate::top_exit_frame_info_offset()), Immediate(0));
@@ -738,10 +740,11 @@
   // Save the old Context pointer. Use RAX as a temporary register.
   // Note that VisitObjectPointers will find this saved Context pointer during
   // GC marking, since it traverses any information between SP and
-  // FP - kExitLinkOffsetInEntryFrame.
+  // FP - kExitLinkSlotFromEntryFp * kWordSize.
   // EntryFrame::SavedContext reads the context saved in this frame.
-  // The constant kSavedContextOffsetInEntryFrame must be kept in sync with
-  // the code below: kSavedContextOffsetInEntryFrame = -9 * kWordSize.
+  // The constant kSavedContextSlotFromEntryFp must be kept in sync with
+  // the code below.
+  ASSERT(kSavedContextSlotFromEntryFp == -9);
   __ movq(RAX, Address(R8, Isolate::top_context_offset()));
   __ pushq(RAX);