Initial support for emitting unwinding information in perf jitdump.

src/perf-jit.h

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 48 matching lines @@
   static const char kFilenameFormatString[];
   static const int kFilenameBufferPadding;
 
   // File buffer size of the low-level log. We don't use the default to
   // minimize the associated overhead.
   static const int kLogBufferSize = 2 * MB;
 
   void LogWriteBytes(const char* bytes, int size);
   void LogWriteHeader();
   void LogWriteDebugInfo(Code* code, SharedFunctionInfo* shared);
+  void LogWriteUnwindingInfo(Code* code);
 
   static const uint32_t kElfMachIA32 = 3;
   static const uint32_t kElfMachX64 = 62;
   static const uint32_t kElfMachARM = 40;
   static const uint32_t kElfMachMIPS = 10;
   static const uint32_t kElfMachARM64 = 183;
 
   uint32_t GetElfMach() {
 #if V8_TARGET_ARCH_IA32
     return kElfMachIA32;
@@ skipping 37 matching lines @@
   void LogRecordedBuffer(AbstractCode* code, SharedFunctionInfo* shared,
                          const char* name, int length) override {
     UNIMPLEMENTED();
   }
 };
 
 #endif  // V8_OS_LINUX
 }  // namespace internal
 }  // namespace v8
 #endif