Silent incorrect behaving when filepath is undefined

[tunnckoCore]

Add check like that and allow passng options.filename, sometimes it is known, so you can detect in the stack and just return that line. So later you can just parse it to get line and column.

  if (!filepath && !options.filename) {
    throw new Error('find-callsite: filepath cant be found, pass opts.filename')
  }
  filepath = filepath || options.filename