[Bug libfortran/117857] libgfortran on powerpc-darwin8 doesn't compile: `-Wint-conversion` in `stream_ttyname`

[glex.spb at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117857

--- Comment #1 from Gleb Mazovetskiy <glex.spb at gmail dot com> ---
On my macOS 10.4 Tiger PowerPC, /usr/include/unistd.h contains the following:

#if __DARWIN_UNIX03
int      ttyname_r(int, char *, size_t) __DARWIN_ALIAS(ttyname_r);
#else /* !__DARWIN_UNIX03 */
char    *ttyname_r(int, char *, size_t);
#endif /* __DARWIN_UNIX03 */