Fix flow errors.

Reviewed by @tolmasky.

packages/babel-parser/src/plugins/estree.js

@@ -4,14 +4,15 @@ import { type TokenType } from "../tokenizer/types";
 import type Parser from "../parser";
 import type { ExpressionErrors } from "../parser/util";
 import * as N from "../types";
+import type { Node as NodeType, NodeBase, File } from "../types";
 import type { Position } from "../util/location";
 import { Errors } from "../parser/error";
 
 const { defineProperty } = Object;
 const toUnenumerable = (object, key) =>
   defineProperty(object, key, { enumerable: false, value: object[key] });
 
-function toESTreeLocation(node) {
+function toESTreeLocation(node: any) {
   toUnenumerable(node.loc.start, "index");
   toUnenumerable(node.loc.end, "index");