[Bug libstdc++/102259] ifstream::read(…, count) fails when count >= 2^31 on darwin

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102259

--- Comment #16 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Yes, I saw the freebsd changes and came to the same conclusion. Looping on 2gb
chunks won't hurt much.

I thought I saw some docs saying >= INT_MAX fails, but maybe I'm wrong. The
Rust change uses INT_MAX - 1