Emit unwinding information for TurboFan code.

src/compiler/unwinding-info-writer.h

Index: src/compiler/unwinding-info-writer.h
diff --git a/src/compiler/unwinding-info-writer.h b/src/compiler/unwinding-info-writer.h
new file mode 100644
index 0000000000000000000000000000000000000000..86f5e9e800b035afeb2f3813a6a33c70a0c4d788
--- /dev/null
+++ b/src/compiler/unwinding-info-writer.h
@@ -0,0 +1,55 @@
+// Copyright 2014 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_COMPILER_UNWINDING_INFO_WRITER_H_
+#define V8_COMPILER_UNWINDING_INFO_WRITER_H_
+
+#if V8_TARGET_ARCH_ARM
+#include "src/compiler/arm/unwinding-info-writer-arm.h"
+#elif V8_TARGET_ARCH_ARM64
+#include "src/compiler/arm64/unwinding-info-writer-arm64.h"
+#elif V8_TARGET_ARCH_X64
+#include "src/compiler/x64/unwinding-info-writer-x64.h"
+#else
+
+// Placeholder for unsupported architectures.
+
+#include "src/base/logging.h"
+
+namespace v8 {
+namespace internal {
+
+class EhFrameWriter;
+
+namespace compiler {
+
+class InstructionBlock;
+
+class UnwindingInfoWriter {
+ public:
+  explicit UnwindingInfoWriter(Zone* zone) {}
+
+  void SetNumberOfInstructionBlocks(int number) {
+    if (FLAG_perf_prof_unwinding_info) UNIMPLEMENTED();
+  }
+
+  void BeginInstructionBlock(int pc_offset, const InstructionBlock* block) {
+    if (FLAG_perf_prof_unwinding_info) UNIMPLEMENTED();
+  }
+  void EndInstructionBlock(const InstructionBlock* block) {
+    if (FLAG_perf_prof_unwinding_info) UNIMPLEMENTED();
+  }
+
+  void Finish(int code_size) {}
+
+  EhFrameWriter* eh_frame_writer() { return nullptr; }
+};
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
+
+#endif
+
+#endif