function fixWindowsSlashes(pattern) {
  return isWindows ? pattern.replace(/\\/g, "/") : pattern;
}
Using backslashes in globs is probably not okay, but not accepting
backslashes as path separators on Windows is even more not okay.
https://github.com/prettier/prettier/pull/6776#discussion_r380723717
https://github.com/mrmlnc/fast-glob#how-to-write-patterns-on-windows
@param {string} pattern