Maintain a FixedArray for the optimized code map.

src/heap/objects-visiting-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_OBJECTS_VISITING_INL_H_
 #define V8_OBJECTS_VISITING_INL_H_
 
 #include "src/heap/array-buffer-tracker.h"
 #include "src/heap/objects-visiting.h"
 #include "src/ic/ic-state.h"
@@ skipping 433 matching lines @@
     Map* map, HeapObject* object) {
   Heap* heap = map->GetHeap();
   SharedFunctionInfo* shared = SharedFunctionInfo::cast(object);
   if (shared->ic_age() != heap->global_ic_age()) {
     shared->ResetForNewContext(heap->global_ic_age());
   }
   if (FLAG_cleanup_code_caches_at_gc) {
     shared->ClearTypeFeedbackInfoAtGCTime();
   }
   if (FLAG_flush_optimized_code_cache) {
-    if (!shared->optimized_code_map()->IsSmi()) {
+    if (!shared->OptimizedCodeMapIsCleared()) {
       // Always flush the optimized code map if requested by flag.
       shared->ClearOptimizedCodeMap();
     }
   } else {
-    if (!shared->optimized_code_map()->IsSmi()) {
+    if (!shared->OptimizedCodeMapIsCleared()) {
       // Treat some references within the code map weakly by marking the
       // code map itself but not pushing it onto the marking deque. The
       // map will be processed after marking.
-      FixedArray* code_map = FixedArray::cast(shared->optimized_code_map());
+      FixedArray* code_map = shared->optimized_code_map();
       MarkOptimizedCodeMap(heap, code_map);
     }
   }
   MarkCompactCollector* collector = heap->mark_compact_collector();
   if (collector->is_code_flushing_enabled()) {
     if (IsFlushable(heap, shared)) {
       // This function's code looks flushable. But we have to postpone
       // the decision until we see all functions that point to the same
       // SharedFunctionInfo because some of them might be optimized.
       // That would also make the non-optimized version of the code
@@ skipping 423 matching lines @@
 
   RelocIterator it(this, mode_mask);
   for (; !it.done(); it.next()) {
     it.rinfo()->template Visit<StaticVisitor>(heap);
   }
 }
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_VISITING_INL_H_