Wrap type-only class fields in flow comments (#11096)

* Wrap type-only class fields in flow comments

* Fix

packages/babel-parser/src/parser/index.js

@@ -1,7 +1,7 @@
 // @flow
 
 import type { Options } from "../options";
-import type { File, JSXOpeningElement } from "../types";
+import type { File /*::, JSXOpeningElement */ } from "../types";
 import type { PluginList } from "../plugin-utils";
 import { getOptions } from "../options";
 import StatementParser from "./statement";
@@ -13,9 +13,11 @@ export type PluginsMap = Map<string, { [string]: any }>;
 
 export default class Parser extends StatementParser {
   // Forward-declaration so typescript plugin can override jsx plugin
+  /*::
   +jsxParseOpeningElementAfterName: (
     node: JSXOpeningElement,
   ) => JSXOpeningElement;
+  */
 
   constructor(options: ?Options, input: string) {
     options = getOptions(options);