[hurd, commited 4/4] chk: Add and fix hidden builtin definitions for *_chk

[Sam James]

Samuel Thibault <samuel.thibault@ens-lyon.org> writes:

> Otherwise on gnu-i686 there are unwanted PLT entries in libc.so when
> fortification is enabled.
>
> Tested for i686-gnu, x86_64-gnu, i686-linux-gnu and x86_64-linux-gnu

Can this one be backported or not because it somewhat affects ABI?

(Not sure if it falls within what we consider stable or not.)

(Will need 41d8c3bc33bcae1ebb8077b0442caef4917f763a too if we do backport.)