memchr
======

POSIX specification:
 https://pubs.opengroup.org/onlinepubs/9699919799/functions/memchr.html

Gnulib module: memchr

Portability problems fixed by Gnulib:

  * This function dereferences too much memory on some platforms: glibc 2.10 on x86_64, IA-64; glibc 2.11 on Alpha, AIX 7.2.

  * This function returns NULL if the character argument is not in the range of an unsigned char on some platforms: Android 5.0.

Portability problems not fixed by Gnulib: