[assembler] Remove unnecessary cast.

src/ppc/assembler-ppc-inl.h

Index: src/ppc/assembler-ppc-inl.h
diff --git a/src/ppc/assembler-ppc-inl.h b/src/ppc/assembler-ppc-inl.h
index f20cbb4eceee25b6326fccc107cf8c40444ba168..6de14de97ad39e76f8d6abb32432ef31bc0b0f2f 100644
--- a/src/ppc/assembler-ppc-inl.h
+++ b/src/ppc/assembler-ppc-inl.h
@@ -297,9 +297,9 @@ void RelocInfo::set_debug_call_address(Address target) {
   DCHECK(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence());
   Assembler::set_target_address_at(isolate_, pc_, host_, target);
   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);
   }
 }