Add MinGW-w64 Makefile target

[jcadduono]

I was having a bit of trouble with Makefile.gcc so I made a few modifications under a new name, ex. Makefile.mingw-w64

Maybe Makefile.mingw would be a better name, as you can probably just use
HOST=i586-pc-mingw32 make -fwin32/Makefile.mingw-w64
to have it compile for 32-bit.

It should happily compile & install to /usr/x86_64-w64-mingw32 with just make -fwin32/Makefile.mingw-w64

It builds both shared and static libraries. You can avoid building the executable files by using:
make lib -fwin32/Makefile.mingw-w64

HOST defaults to x86_64-w64-mingw32.
Install location can be set with PREFIX. (defaults to /usr/$HOST)

root@gallifrey:/home/jc/build/lib/zlib# make -fwin32/Makefile.mingw-w64
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o adler32.o adler32.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o compress.o compress.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o crc32.o crc32.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o deflate.o deflate.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o gzclose.o gzclose.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o gzlib.o gzlib.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o gzread.o gzread.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o gzwrite.o gzwrite.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o infback.o infback.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o inffast.o inffast.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o inflate.o inflate.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o inftrees.o inftrees.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o trees.o trees.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o uncompr.o uncompr.c
x86_64-w64-mingw32-gcc  -O3 -Wall -c -o zutil.o zutil.c
x86_64-w64-mingw32-ar rcs libz.a adler32.o compress.o crc32.o deflate.o gzclose.o gzlib.o gzread.o gzwrite.o infback.o inffast.o inflate.o inftrees.o trees.o uncompr.o zutil.o 
x86_64-w64-mingw32-windres --define GCC_WINDRES -o zlibrc.o win32/zlib1.rc
x86_64-w64-mingw32-gcc -shared -Wl,--out-implib,libz.dll.a  \
-o zlib1.dll win32/zlib.def adler32.o compress.o crc32.o deflate.o gzclose.o gzlib.o gzread.o gzwrite.o infback.o inffast.o inflate.o inftrees.o trees.o uncompr.o zutil.o  zlibrc.o
x86_64-w64-mingw32-strip zlib1.dll
x86_64-w64-mingw32-gcc  -O3 -Wall -I. -c -o example.o test/example.c
x86_64-w64-mingw32-gcc  -o example.exe example.o libz.a
x86_64-w64-mingw32-strip example.exe
x86_64-w64-mingw32-gcc  -O3 -Wall -I. -c -o minigzip.o test/minigzip.c
x86_64-w64-mingw32-gcc  -o minigzip.exe minigzip.o libz.a
x86_64-w64-mingw32-strip minigzip.exe
x86_64-w64-mingw32-gcc  -o example_d.exe example.o libz.dll.a
x86_64-w64-mingw32-strip example_d.exe
x86_64-w64-mingw32-gcc  -o minigzip_d.exe minigzip.o libz.dll.a
x86_64-w64-mingw32-strip minigzip_d.exe
root@gallifrey:/home/jc/build/lib/zlib# 

Successfully managed to use zlib1.dll under nginx.exe :)

[Neustradamus]

@madler: It is possible to look this PR?

[dbjh]

With all due respect, but what does this PR address? The provided reason is "a bit of trouble with Makefile.gcc". The PR is from 7 years ago. I tried win32/Makefile.gcc today, as well as running configure and then just running make. Both appear to work with GCC 13 as part of MinGW-w64.

[pmqs]

That reminds me -- I have a workflow that will test the MinGW variants. Will see if I can find it.

[pmqs]

See #935 for the MinGW build