Replace SetObjectProperty / DefineObjectProperty with less powerful alternatives where relevant.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index bd9e4abe71354c1936cb5bac273dfa645fc2a0cb..5ce906152bf6e4b886dc2fe3d250ac6ad159cc98 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -1176,9 +1176,6 @@ class Object {
   MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyProperty(
       Isolate* isolate, Handle<Object> reciever, Handle<Object> name,
       Handle<Object> value, LanguageMode language_mode);
-  MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyElement(
-      Isolate* isolate, Handle<Object> receiver, uint32_t index,
-      Handle<Object> value, LanguageMode language_mode);
   MUST_USE_RESULT static MaybeHandle<Object> RedefineNonconfigurableProperty(
       Isolate* isolate, Handle<Object> name, Handle<Object> value,
       LanguageMode language_mode);
@@ -1841,6 +1838,12 @@ class JSObject: public JSReceiver {
   MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithInterceptor(
       LookupIterator* it, Handle<Object> value);
 
+  // Calls SetOwn[Property|Element]IgnoreAttributes depending on whether name is
+  // convertible to an index.
+  MUST_USE_RESULT static inline MaybeHandle<Object> DefinePropertyOrElement(
+      Handle<JSObject> object, Handle<Name> name, Handle<Object> value,
+      PropertyAttributes attributes = NONE);
+
   MUST_USE_RESULT static MaybeHandle<Object> SetOwnPropertyIgnoreAttributes(
       Handle<JSObject> object, Handle<Name> name, Handle<Object> value,
       PropertyAttributes attributes);
@@ -4045,7 +4048,7 @@ class ScopeInfo : public FixedArray {
   FunctionKind function_kind();
 
   // Copies all the context locals into an object used to materialize a scope.
-  static bool CopyContextLocalsToScopeObject(Handle<ScopeInfo> scope_info,
+  static void CopyContextLocalsToScopeObject(Handle<ScopeInfo> scope_info,
                                              Handle<Context> context,
                                              Handle<JSObject> scope_object);