Enhance SafeStackFrameIterator to avoid triggering assertions in debug mode.

src/x64/frames-x64.cc

 // Copyright 2009 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 17 matching lines @@
 #include "v8.h"
 
 #if defined(V8_TARGET_ARCH_X64)
 
 #include "frames-inl.h"
 
 namespace v8 {
 namespace internal {
 
 
-
-
-StackFrame::Type ExitFrame::GetStateForFramePointer(Address fp, State* state) {
-  if (fp == 0) return NONE;
-  // Compute the stack pointer.
-  Address sp = Memory::Address_at(fp + ExitFrameConstants::kSPOffset);
-  // Fill in the state.
-  state->fp = fp;
-  state->sp = sp;
-  state->pc_address = reinterpret_cast<Address*>(sp - 1 * kPointerSize);
-  ASSERT(*state->pc_address != NULL);
-  return EXIT;
+Address ExitFrame::ComputeStackPointer(Address fp) {
+  return Memory::Address_at(fp + ExitFrameConstants::kSPOffset);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64