[strong] Implement strong mode restrictions on property access

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 19e92df0f189d9eca4804676c4c692cb5487f2f8..94949d4b5ab663a2fac8d4561552099a9d2c54e9 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -1155,7 +1155,8 @@ class Object {
   MUST_USE_RESULT static inline MaybeHandle<Smi> ToSmi(Isolate* isolate,
                                                        Handle<Object> object);
 
-  MUST_USE_RESULT static MaybeHandle<Object> GetProperty(LookupIterator* it);
+  MUST_USE_RESULT static MaybeHandle<Object> GetProperty(
+      LookupIterator* it, Strength strength = Strength::WEAK);
 
   // Implementation of [[Put]], ECMA-262 5th edition, section 8.12.5.
   MUST_USE_RESULT static MaybeHandle<Object> SetProperty(
@@ -1188,16 +1189,17 @@ class Object {
       LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
       LanguageMode language_mode, StoreFromKeyed store_mode);
   MUST_USE_RESULT static inline MaybeHandle<Object> GetPropertyOrElement(
-      Handle<Object> object, Handle<Name> name);
+      Handle<Object> object, Handle<Name> name,
+      Strength strength = Strength::WEAK);
   MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty(
-      Isolate* isolate,
-      Handle<Object> object,
-      const char* key);
+      Isolate* isolate, Handle<Object> object, const char* key,
+      Strength strength = Strength::WEAK);
   MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty(
-      Handle<Object> object, Handle<Name> name);
+      Handle<Object> object, Handle<Name> name,
+      Strength strength = Strength::WEAK);
 
   MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithAccessor(
-      LookupIterator* it);
+      LookupIterator* it, Strength strength);
   MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithAccessor(
       Handle<Object> receiver, Handle<Name> name, Handle<Object> value,
       Handle<JSObject> holder, Handle<Object> structure,
@@ -1212,9 +1214,8 @@ class Object {
       Handle<Object> value);
 
   MUST_USE_RESULT static inline MaybeHandle<Object> GetElement(
-      Isolate* isolate,
-      Handle<Object> object,
-      uint32_t index);
+      Isolate* isolate, Handle<Object> object, uint32_t index,
+      Strength strength = Strength::WEAK);
 
   MUST_USE_RESULT static MaybeHandle<Object> SetElementWithReceiver(
       Isolate* isolate, Handle<Object> object, Handle<Object> receiver,
@@ -2324,7 +2325,7 @@ class JSObject: public JSReceiver {
 
   // Used from Object::GetProperty().
   MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithFailedAccessCheck(
-      LookupIterator* it);
+      LookupIterator* it, Strength strength);
 
   MUST_USE_RESULT static MaybeHandle<Object> SetElementWithCallback(
       Handle<Object> object, Handle<Object> structure, uint32_t index,