Crash when parse hashbang with `{tokens: true}`

[fisker]

Flow version: 0.202.0

Expected behavior

> require('flow-parser').parse('#!/usr/bin/env node\n', {tokens: true})
<CWD>\node_modules\flow-parser\flow_parser.js:807
throw a}function
^

Error: Internal error: Offset_utils.Offset_lookup_failed(_, "Failure while looking up column. Index: -1. Length: 1.")

\n after hashbang is required to reproduce.

Actual behavior

• Link to Try-Flow or Github repo:

[fisker]

Any progress here?