coro-fs readFile fails on /proc files

[aiverson]

When using coro-fs on files in /proc, readFile incorrectly returns empty strings.

Using the luvit fs readFileSync and readFile functions works correctly and returns the correct contents, matching what is produced by cat.

Some files this bug can be reproduced on are /proc/stat, /proc/cgroups, /proc/modules, /proc/mounts