Revert of Revert of [strong] Implement strong mode restrictions on property access

src/ic/handler-compiler.cc

 // Copyright 2014 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.
 
 #include "src/v8.h"
 
 #include "src/cpu-profiler.h"
 #include "src/ic/call-optimization.h"
 #include "src/ic/handler-compiler.h"
 #include "src/ic/ic.h"
@@ skipping 519 matching lines @@
                           receiver(), scratch2(), true, value(), holder,
                           accessor_index);
   return GetCode(kind(), Code::FAST, name);
 }
 
 
 #undef __
 
 
 void ElementHandlerCompiler::CompileElementHandlers(
-    MapHandleList* receiver_maps, CodeHandleList* handlers) {
+    MapHandleList* receiver_maps, CodeHandleList* handlers,
+    LanguageMode language_mode) {
   for (int i = 0; i < receiver_maps->length(); ++i) {
     Handle<Map> receiver_map = receiver_maps->at(i);
     Handle<Code> cached_stub;
 
     if (receiver_map->IsStringMap()) {
       cached_stub = LoadIndexedStringStub(isolate()).GetCode();
     } else if (receiver_map->instance_type() < FIRST_JS_RECEIVER_TYPE) {
       cached_stub = isolate()->builtins()->KeyedLoadIC_Slow();
     } else {
       bool is_js_array = receiver_map->instance_type() == JS_ARRAY_TYPE;
       ElementsKind elements_kind = receiver_map->elements_kind();
 
       // No need to check for an elements-free prototype chain here, the
       // generated stub code needs to check that dynamically anyway.
       bool convert_hole_to_undefined =
-          is_js_array && elements_kind == FAST_HOLEY_ELEMENTS &&
-          *receiver_map == isolate()->get_initial_js_array_map(elements_kind);
+          (is_js_array && elements_kind == FAST_HOLEY_ELEMENTS &&
+           *receiver_map ==
+               isolate()->get_initial_js_array_map(elements_kind)) &&
+          !is_strong(language_mode);
 
       if (receiver_map->has_indexed_interceptor()) {
         cached_stub = LoadIndexedInterceptorStub(isolate()).GetCode();
       } else if (IsSloppyArgumentsElements(elements_kind)) {
         cached_stub = KeyedLoadSloppyArgumentsStub(isolate()).GetCode();
       } else if (IsFastElementsKind(elements_kind) ||
                  IsExternalArrayElementsKind(elements_kind) ||
                  IsFixedTypedArrayElementsKind(elements_kind)) {
         cached_stub = LoadFastElementStub(isolate(), is_js_array, elements_kind,
                                           convert_hole_to_undefined).GetCode();
       } else {
         DCHECK(elements_kind == DICTIONARY_ELEMENTS);
-        cached_stub = LoadDictionaryElementStub(isolate()).GetCode();
+        LoadICState state = LoadICState(
+            is_strong(language_mode) ? LoadICState::kStrongModeState : 0);
+        cached_stub = LoadDictionaryElementStub(isolate(), state).GetCode();
       }
     }
 
     handlers->Add(cached_stub);
   }
 }
 }  // namespace internal
 }  // namespace v8