Problem: Shebang filetype detection can be improved
Solution: Improve detection logic (Eisuke Kawashima)
Vim does not correctly detect filetype from
- `#!/usr/bin/env --split-string=awk -f`
- `#!/usr/bin/env -S -i awk -f`
- `#!/usr/bin/env -S VAR= awk -f`
So update the current detection logic to detect those cases.
closes: vim/vim#17199f102f4c2e8
Co-authored-by: Eisuke Kawashima <e-kwsm@users.noreply.github.com>