Reland Implement .eh_frame writer and disassembler.

src/x64/eh-frame-x64.cc

Index: src/x64/eh-frame-x64.cc
diff --git a/src/x64/eh-frame-x64.cc b/src/x64/eh-frame-x64.cc
new file mode 100644
index 0000000000000000000000000000000000000000..6104e023256923aa16589ae61b346283053e496e
--- /dev/null
+++ b/src/x64/eh-frame-x64.cc
@@ -0,0 +1,25 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/x64/eh-frame-x64.h"
+
+namespace v8 {
+namespace internal {
+
+const char* GetRegisterName(int register_number) {
+  switch (register_number) {
+    case 6:
+      return "rbp";
+    case 7:
+      return "rsp";
+    case 16:
+      return "rip";
+    default:
+      UNIMPLEMENTED();
+      return nullptr;
+  }
+}
+
+}  // namespace internal
+}  // namespace v8