Introduce architecture specific headers describing Dart stack frames.

runtime/vm/stack_frame_x64.h

Index: runtime/vm/stack_frame_x64.h
===================================================================
--- runtime/vm/stack_frame_x64.h	(revision 0)
+++ runtime/vm/stack_frame_x64.h	(revision 0)
@@ -0,0 +1,33 @@
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#ifndef VM_STACK_FRAME_X64_H_
+#define VM_STACK_FRAME_X64_H_
+
+namespace dart {
+
+/* X64 Dart Frame Layout
+
+               |                   | <- TOS
+Callee frame   | ...               |
+               | current ret addr  |    (PC of current frame)
+               +-------------------+
+Current frame  | ...               | <- RSP of current frame
+               | first local       |
+               | PC Marker         |    (current frame's code entry)
+               | caller's RBP      | <- RBP of current frame
+               | caller's ret addr |    (PC of caller frame)
+               +-------------------+
+Caller frame   | last parameter    |
+               |  ...              |
+*/
+
+static const int kLastParamSlotIndex = 2;  // From fp.
+static const int kFirstLocalSlotIndex = -2;  // From fp.
+static const int kPcSlotIndexFromSp = -1;
+
+}  // namespace dart
+
+#endif  // VM_STACK_FRAME_X64_H_
+