Ever since an old patch version, it has (for reasonable security
reasons) not supported patched with ../ in the filename.
Many of our patches have been relying on this behaviour being OK,
because we start off with an ancient patch version that didn't perform
such checks. As soon as we need this behaviour after we build a newer
patch though, we will have problems.
So, let's change the policy.
Patches are relative to where tarballs are extracted, rather than the
"working directory" - e.g. have patches for `coreutils-9.4/src/cp.c`
instead of `src/cp.c`.
Keeping this consistent has a few implications;
- patches are applied from the build/ directory in bash era now, with
`-p0`
- when patches are manually applied in the bash era, use `-p` as
required, usually `-p1`
- in kaem era where patches are always manually applied, `-p1` is used
This replaces the previous sed hackery with a proper patch, and removes
a few more libc functions that meslibc is missing.
The binary name is changed to "byacc" so it doesn't get overwritten by
heirloom yacc.
The bsearch() replacement code comes from an earlier version of byacc.
