[ESNext] Implement DynamicImportCall

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index f43fd8f6009afa8004ce9dde495c8147638c1711..9ea7d71753877ea4aea9bfceeeec70dfd9edbc8d 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -289,6 +289,9 @@ class V8_EXPORT_PRIVATE Factory final {
   Handle<Symbol> NewSymbol();
   Handle<Symbol> NewPrivateSymbol();
 
+  // Create a promise.
+  Handle<JSPromise> NewJSPromise();
+
   // Create a global (but otherwise uninitialized) context.
   Handle<Context> NewNativeContext();