Reland remaining parts of 'Use weak cells in map checks in polymorphic ICs'

src/ic/x64/ic-compiler-x64.cc

Index: src/ic/x64/ic-compiler-x64.cc
diff --git a/src/ic/x64/ic-compiler-x64.cc b/src/ic/x64/ic-compiler-x64.cc
index a5848b6dda231369ee78e984bf8542de1487027c..c6622e5fdd5d924575e4e3f2bbfb1c692a237bc0 100644
--- a/src/ic/x64/ic-compiler-x64.cc
+++ b/src/ic/x64/ic-compiler-x64.cc
@@ -42,20 +42,22 @@ Handle<Code> PropertyICCompiler::CompileKeyedStorePolymorphic(
     MapHandleList* receiver_maps, CodeHandleList* handler_stubs,
     MapHandleList* transitioned_maps) {
   Label miss;
-  __ JumpIfSmi(receiver(), &miss, Label::kNear);
+  __ JumpIfSmi(receiver(), &miss);
 
-  __ movp(scratch1(), FieldOperand(receiver(), HeapObject::kMapOffset));
+  Register map_reg = scratch1();
+  __ movp(map_reg, FieldOperand(receiver(), HeapObject::kMapOffset));
   int receiver_count = receiver_maps->length();
   for (int i = 0; i < receiver_count; ++i) {
+    Handle<WeakCell> cell = Map::WeakCellForMap(receiver_maps->at(i));
     // Check map and tail call if there's a match
-    __ Cmp(scratch1(), receiver_maps->at(i));
+    __ CmpWeakValue(map_reg, cell, scratch2());
     if (transitioned_maps->at(i).is_null()) {
       __ j(equal, handler_stubs->at(i), RelocInfo::CODE_TARGET);
     } else {
       Label next_map;
       __ j(not_equal, &next_map, Label::kNear);
-      __ Move(transition_map(), transitioned_maps->at(i),
-              RelocInfo::EMBEDDED_OBJECT);
+      Handle<WeakCell> cell = Map::WeakCellForMap(transitioned_maps->at(i));
+      __ LoadWeakValue(transition_map(), cell, &miss);
       __ jmp(handler_stubs->at(i), RelocInfo::CODE_TARGET);
       __ bind(&next_map);
     }
@@ -109,8 +111,9 @@ Handle<Code> PropertyICCompiler::CompilePolymorphic(TypeHandleList* types,
     Handle<Map> map = IC::TypeToMap(*type, isolate());
     if (!map->is_deprecated()) {
       number_of_handled_maps++;
+      Handle<WeakCell> cell = Map::WeakCellForMap(map);
       // Check map and tail call if there's a match
-      __ Cmp(map_reg, map);
+      __ CmpWeakValue(map_reg, cell, scratch2());
       if (type->Is(HeapType::Number())) {
         DCHECK(!number_case.is_unused());
         __ bind(&number_case);