Refactor ObjectVisitor functions to not mutate the slot.

src/heap/mark-compact.cc

Index: src/heap/mark-compact.cc
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index ad0c58e4a8d53e61c5c459caec33d9299184d065..126b87c034e4448e489af9390ea0df53aa9b54ef 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -2850,6 +2850,16 @@ class PointersUpdatingVisitor : public ObjectVisitor {
     }
   }
 
+  void VisitCodeEntry(Address entry_address) override {
+    Object* code = Code::GetObjectFromEntryAddress(entry_address);
+    Object* old_code = code;
+    VisitPointer(&code);
+    if (code != old_code) {
+      Memory::Address_at(entry_address) =
+          reinterpret_cast<Code*>(code)->entry();
+    }
+  }
+
   void VisitDebugTarget(RelocInfo* rinfo) override {
     DCHECK(RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
            rinfo->IsPatchedDebugBreakSlotSequence());