Reland Implement .eh_frame writer and disassembler.

src/arm64/eh-frame-arm64.h

+// 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.
+
+#ifndef V8_ARM64_EH_FRAME_ARM64_H_
+#define V8_ARM64_EH_FRAME_ARM64_H_
+
+#include "src/macro-assembler.h"
+
+namespace v8 {
+namespace internal {
+
+static const Register& kInitialBaseRegister = x29;
+static const int kInitialBaseOffset = 0;
+static const int kDataAlignmentFactor = 8;
+#ifdef ENABLE_DISASSEMBLER
+static const int kInitialStateOffsetInCIE = 19;
+#endif
+
+// The code and data alignments are a bit unorthodox, but they suit our purpose.
+static const byte kCIE[] = {
+    0x14, 0x00, 0x00, 0x00,  // Size of the CIE excluding this field
+    0x00, 0x00, 0x00, 0x00,  // CIE identifier, always 0
+    3,                       // CIE version 3
+    0x7a, 0x4c, 0x52, 0x00,  // Augmentation string zLR
+    1,                       // Code alignment factor
+    8,                       // Data alignment factor
+    30,                      // Return address register: lr (r30)
+    2,                       // Length of augmentation data
+    0xff,                    // No LSDA
+    0x1b,                    // FDE pointers encoding: kSData4 | kPcRel
+    // Initial state
+    0x0c, 29, kInitialBaseOffset,  // base = fp+0
+    0x08, 30,                      // lr is valid
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif