rm unneded regex

build/files.js

@@ -175,20 +175,7 @@ const headRegexp = /(^module.exports = \w+;?)/m
     /require\('internal\/streams\/BufferList'\)/,
     'require(\'./internal/streams/BufferList\')'
   ]
-  , prependFix = [
-    /var prependListener;\n(?:.|\n)+\[fn, emitter\._events\[event]];\n\s\s};\n}/m,
-    `function prependListener(emitter, event, fn) {
-      if (typeof emitter.prependListener === 'function') {
-        return emitter.prependListener(event, fn);
-      } else {
-        // This is a hack to make sure that our error handler is attached before any
-        // userland ones.  NEVER DO THIS. This is here only because this code needs
-        // to continue to work with older versions of Node.js that do not include
-        // the prependListener() method. The goal is to eventually remove this hack.
-        if (!emitter._events || !emitter._events[event]) emitter.on(event, fn);else if (isArray(emitter._events[event])) emitter._events[event].unshift(fn);else emitter._events[event] = [fn, emitter._events[event]];
-      }
-    }`
-  ]
+
 
 module.exports['_stream_duplex.js'] = [
     requireReplacement
@@ -234,7 +221,6 @@ module.exports['_stream_readable.js'] = [
   , bufferShimFix
   , bufferStaticMethods
   , internalDirectory
-  , prependFix
 ]
 
 module.exports['_stream_transform.js'] = [