[PATCH v3] Remove defines to builtins in string2.h

[Wilco Dijkstra]

Florian Weimer wrote:

> -#ifndef _HAVE_STRING_ARCH_strchr
> -# define strchr(s, c) __builtin_strchr (s, c)
> -#endif

> Current master has this:
...
> So I'm afraid the patch doesn't apply.

Yes there is overlap with this patch: https://sourceware.org/ml/libc-alpha/2016-11/msg00586.html
(a previous version of that was posted back in February...). This particular
change could be rolled back into the original strchr patch to avoid this conflict.

You may also need my recent strtok and strsep patches although I think there should
be no direct conflicts like the above.

Wilco