Move webpack hack to a separate file

Author: aminya

src/master/implementation.node.ts

@@ -10,18 +10,14 @@ import {
   ThreadsWorkerOptions,
   WorkerImplementation
 } from "../types/master"
+import { isWebpack, requireFunction, __non_webpack_require__ } from '../webpack-hack'
 
 interface WorkerGlobalScope {
   addEventListener(eventName: string, listener: (event: Event) => void): void
   postMessage(message: any, transferables?: any[]): void
   removeEventListener(eventName: string, listener: (event: Event) => void): void
 }
 
-// TODO remove webpack hacks. These hurt the performance for non-web-pack situations
-// Webpack hack
-declare let __non_webpack_require__: typeof require
-const isWebpack = typeof __non_webpack_require__ === "function"
-const requireFunction: typeof require = isWebpack ? __non_webpack_require__ : eval("require")
 
 declare const self: WorkerGlobalScope
 

src/webpack-hack.ts

@@ -0,0 +1,7 @@
+// tslint:disable no-eval
+
+// TODO remove webpack hacks. These hurt the performance for non-web-pack situations
+// Webpack hack
+export declare let __non_webpack_require__: typeof require
+export const isWebpack = typeof __non_webpack_require__ === "function"
+export const requireFunction: typeof require = isWebpack ? __non_webpack_require__ : eval("require")