fixup! fixup! path: fix posix.relative() on Windows

Author: Trott

test/parallel/test-path-resolve.js

@@ -12,7 +12,7 @@ const backslashRE = /\\/g;
 const posixyCwd = common.isWindows ?
   (() => {
     const _ = process.cwd()
-      .replace(new RegExp(`\\${path.sep}`, 'g'), path.posix.sep);
+      .replaceAll(path.sep, path.posix.sep);
     return _.substr(_.indexOf(path.posix.sep));
   })() :
   process.cwd();