Create File class for babel helpers (#10575)

* add test

* fix: pass File to helper traverser

* pass babel.File to helpers.ensure

packages/babel-core/src/tools/build-external-helpers.js

@@ -2,6 +2,7 @@ import * as helpers from "@babel/helpers";
 import generator from "@babel/generator";
 import template from "@babel/template";
 import * as t from "@babel/types";
+import File from "../transformation/file/file";
 
 // Wrapped to avoid wasting time parsing this when almost no-one uses
 // build-external-helpers.
@@ -136,6 +137,7 @@ function buildHelpers(body, namespace, whitelist) {
 
     const ref = (refs[name] = getHelperReference(name));
 
+    helpers.ensure(name, File);
     const { nodes } = helpers.get(name, getHelperReference, ref);
 
     body.push(...nodes);

packages/babel-core/src/transformation/file/file.js

@@ -174,7 +174,7 @@ export default class File {
     }
 
     // make sure that the helper exists
-    helpers.ensure(name);
+    helpers.ensure(name, File);
 
     const uid = (this.declarations[name] = this.scope.generateUidIdentifier(
       name,