Since commit e65d1e69e88268145ff0e7e73240f028885915be there is no longer an
io.FileIO class, so this option is no longer needed.
This option also controlled whether or not files supported being opened in
binary mode (eg 'rb'), and could, if disabled, lead to confusion as to why
opening a file in binary mode silently did the wrong thing (it would just
open in text mode if MICROPY_PY_IO_FILEIO was disabled).
The various VFS implementations (POSIX, FAT, LFS) were the only places
where enabling this option made a difference, and in almost all cases where
one of these filesystems were enabled, MICROPY_PY_IO_FILEIO was also
enabled. So it makes sense to just unconditionally enable this feature
(ability to open a file in binary mode) in all cases, and so just remove
this config option altogether. That makes configuration simpler and means
binary file support always exists (and opening a file in binary mode is
arguably more fundamental than opening in text mode, so if anything should
be configurable then it should be the ability to open in text mode).
Signed-off-by: Damien George <damien@micropython.org>
8f4c108025