WIP SharedArrayBuffer implementation

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index 600f312927e144bb20d93b7a6db72be2effe592c..4a8f9be512932219aa149b6f068ca5fd2b4c00a9 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -444,16 +444,18 @@ class Factory final {
 
   Handle<JSGeneratorObject> NewJSGeneratorObject(Handle<JSFunction> function);
 
-  Handle<JSArrayBuffer> NewJSArrayBuffer();
+  Handle<JSArrayBuffer> NewJSArrayBuffer(SharedFlag is_shared = NOT_SHARED);
 
-  Handle<JSTypedArray> NewJSTypedArray(ExternalArrayType type);
+  Handle<JSTypedArray> NewJSTypedArray(ExternalArrayType type,
+                                       SharedFlag is_shared = NOT_SHARED);
 
   Handle<JSTypedArray> NewJSTypedArray(ElementsKind elements_kind);
 
   // Creates a new JSTypedArray with the specified buffer.
   Handle<JSTypedArray> NewJSTypedArray(ExternalArrayType type,
                                        Handle<JSArrayBuffer> buffer,
-                                       size_t byte_offset, size_t length);
+                                       size_t byte_offset, size_t length,
+                                       SharedFlag is_shared = NOT_SHARED);
 
   // Creates a new on-heap JSTypedArray.
   Handle<JSTypedArray> NewJSTypedArray(ElementsKind elements_kind,