[assembler] Remove unnecessary cast.

src/x64/assembler-x64-inl.h

 // Copyright 2012 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_X64_ASSEMBLER_X64_INL_H_
 #define V8_X64_ASSEMBLER_X64_INL_H_
 
 #include "src/x64/assembler-x64.h"
 
 #include "src/base/cpu.h"
@@ skipping 496 matching lines @@
 
 
 void RelocInfo::set_debug_call_address(Address target) {
   DCHECK(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence());
   Memory::Address_at(pc_ + Assembler::kPatchDebugBreakSlotAddressOffset) =
       target;
   Assembler::FlushICache(isolate_,
                          pc_ + Assembler::kPatchDebugBreakSlotAddressOffset,
                          sizeof(Address));
   if (host() != NULL) {
-    Object* target_code = Code::GetCodeFromTargetAddress(target);
-    host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
-        host(), this, HeapObject::cast(target_code));
+    Code* target_code = Code::GetCodeFromTargetAddress(target);
+    host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(host(), this,
+                                                                  target_code);
   }
 }
 
 template <typename ObjectVisitor>
 void RelocInfo::Visit(Isolate* isolate, ObjectVisitor* visitor) {
   RelocInfo::Mode mode = rmode();
   if (mode == RelocInfo::EMBEDDED_OBJECT) {
     visitor->VisitEmbeddedPointer(this);
     Assembler::FlushICache(isolate, pc_, sizeof(Address));
   } else if (RelocInfo::IsCodeTarget(mode)) {
@@ skipping 80 matching lines @@
 void Operand::set_disp64(int64_t disp) {
   DCHECK_EQ(1, len_);
   int64_t* p = reinterpret_cast<int64_t*>(&buf_[len_]);
   *p = disp;
   len_ += sizeof(disp);
 }
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_X64_ASSEMBLER_X64_INL_H_