_IO_fwide() is defined in libio.h file. This file is included only
when _LIBC is defined.
So, in case of compilation of these files without _LIBC definition,
the compilation failed due to this unknown function.
Now this function is called when libio.h file is included.
(Change merged from gnulib. Tested on x86_64.)
* argp/argp-fmtstream.c (__argp_fmtstream_update): Use [_LIBC]
conditional on calls to _IO_fwide and putwc_unlocked. (Merge from
gnulib.)
* argp/argp-help.c (__argp_failure): Likewise.
3a67e81d75