depend-cleanup: bea89d038ac5 also moved memchr

[emaste]

Summary

Commit bea89d038ac5 added strlcat but also introduced a memchr wrapper
in the source tree rather than using the autogenerated one used for
AARCH64_STRING_FUNCS.  Move memchr.S to MDSRS and add a cleanup rule for
the old wrapper.

Fixes: bea89d038ac5 ("lib/libc/aarch64/string: add strlcat SIMD implementation")

[emaste]

lib/libc/aarch64/string/Makefile.inc

21

We're still using Arm's memchr, but have a wrapper in the src tree rather than using the generated one below.

[jrtc27]

Uh, why do we need that wrapper instead of just calling memchr itself?

[fuz]

Sorry for missing this one too. All these build system hacks are confusing.

[emaste]

Uh, why do we need that wrapper instead of just calling memchr itself?

The wrapper is just including arm-optimized-routines memchr.S as the autogenerated one does, and the net effect is to switch from #define __memchr_aarch64 memchr to .set memchr __memchr_aarch64. I guess we need a more holistic cleanup of this.