[assembler] Remove unnecessary cast.

src/mips/assembler-mips-inl.h

Index: src/mips/assembler-mips-inl.h
diff --git a/src/mips/assembler-mips-inl.h b/src/mips/assembler-mips-inl.h
index b06d7ce437e88f258cd280d105bae97fd219dd6b..472adb1cded11594b20e94487b31eb79e52df9ef 100644
--- a/src/mips/assembler-mips-inl.h
+++ b/src/mips/assembler-mips-inl.h
@@ -335,9 +335,9 @@ void RelocInfo::set_debug_call_address(Address target) {
   // sequence.
   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);
   }
 }