[PATCH v2] io: Use gnulib fts implementation (BZ 22944, BZ 20331)

[Wilco Dijkstra]

Hi Collin,

> size_t val = stdc_rotate_right ((size_t) data, 3);

> That is a C2y function right? I don't think we can use it. Looking at
> the releases with the relevant commit:

See stdlib/stdbit.h - it supports all GCC releases even with hacks for GCC 3.4!

(hence my proposal to drop support for such old compilers)

Cheers,
Wilco