Fix builds on latest clang

[hpckurt]

This PR fixes builds on the latest clang versions. Tested and verified on MacOS 26. zlib needs to be updated since the previously included 1.1.4 no longer builds.

[hpckurt]

Mentioning @wscott for visibility

[wscott]

Yeah, I saw it the first time, but haven't gotten around to trying this out.
My first impression was that I wasn't sure we should include a full copy of the zlibc release instead of just the sources.
Or if it should just download the sources if a local copy isn't found.

[hpckurt]

Ah, sorry for the ping then. I included the full zlib sources since that's what was previously included in the src/libc directory. It doesn't really matter how it's handled as long as the updated zlib source is seen at build time.

[wscott]

You should be able to do a build on MacOS in a fresh clone by only typing make in the src subdir.

These are the fixes I noticed. I was going to just push changes but I don't think I can.

[wscott]

This line is pointless and in fact the whole block can be removed because it already happens in mkconf.sh

[wscott]

This was not the original Makefile, but a wrapper used by the larger build. You shouldn't be building this yourself.

For me this worked:

zlib.fake:
	$(MAKE) -C.. zlib

ZLIB_OBJS = $(patsubst %,zlib/%, \
	adler32.o \
	compress.o crc32.o \
	deflate.o \
	infback.o inffast.o inflate.o inftrees.o \
	trees.o \
	uncompr.o \
	zutil.o)

ZLIB_HDRS = $(patsubst %,zlib/%, \
	crc32.h deflate.h gzguts.h inffast.h inffixed.h inflate.h \
	inftrees.h trees.h zconf.h zlib.h zutil.h \
	)


zlib: $(ZLIB_OBJS)