Simple contribution please?

[Samuel Thibault]

Hello,

It becomes more and more clear that we shouldn't steal functions from
glibc into gnumach, it poses cross-building issues from Linux.

Could somebody contribute, or steal from a BSD the following functions,
to be included in gnumach/kern/strings.c?

- memcmp
- memcpy
- memmove
- strchr
- strsep
- strstr

Thanks,
Samuel