Svn up and resolved conflicts.

r347984 creates conflicts for lio_bsd.h and if_cdce.c.
I need to svn up and rebase.

More _KERNEL adjustments.

Remove one more extra prototype.

Replace ifdef USERSPACE_TESTING to ifndef _KERNEL.

It looks this change hasn't yet committed.

Delete unneeded comments and put 2019 May.

This change requires https://reviews.freebsd.org/D20193 to address duplicate crc32() API between zlib and libkern.h.
I will make some minor adjustments after that's done.

Don't touch ZFS module, yet.

I split the original change-set to multiple ones.

I was able to link both old and new versions of zlib at same time over weekend.
So, this change became no longer immediate blocker.
I thought it would be nicer to address zlib conversion in a single commit instead of two commits once upon time.

Exclude unintended files... :(

Delete comments about usage of STD_PROBE5.

It looks I can put 2 versions of zlib into kernel.
Let's wait and see.

Rename libkern/crc32.c to libkern/kern_crc32.c to avoid having same object
filename as zlib/crc32.c.

I'd like to rename libkern/crc32.c to libkern/kern_crc32.c so that we don't get object filename conflict with zlib/crc32.c as well.
I'm having difficulties with arc diff...

Fixed function prototype style.

Combine SCTP cases.

Exclude unintended change.

Relocation of contrib/zlib to sys/contrib/zilb is making the biggest noise in the diff.

Deleted uncalled functions from ng_zlib.c and reverted z_ prefixes.

Reverted aout.4 and also add "zlib" in sys/conf/files (I think we need this for "device").

Use zlib uncompress function and updated README.

Created "device zlib" and updated dependencies.

Deleted sys/inflate.h from mips and i386's kgzip and kgzldr.

Removed personal notes.

Both buildworld and buildkernel finises without a problem.

Use bsd.kmod.mk to share ZLIB_CFLAGS.

Moved contrib/zlib to sys/contrib/zlib.

Created own std header wrapper instead of using zstd's.

Few changes were missed in the last review.

ZLIB was modified to compile with -DNO_GZIP to avoid including stdlib.h once.
However, ZFS uses GZIP in its own zlib clone and thus adjusted again to work
ZLIB without -DNO_GZIP.
With ZFS's zconf.h, ZLIB symols were renamed to z_* and few of them were zz_*.
zmod implementatoins are prefixed with zmod_* to avoid conflicts.

Actually zfs uses zlib but its own copy, zmod, and it has few extra funcions.

Thanks.
A couple of month delay is a minor.
I just started thinking to add few more enhancements.
It will be nice if you pick up next one, too ( coming in a couple of months, too).

Uncomment some of zlib prototypes to ensuring they are static functions.

-Wno-cast-qual for deflate.c only.

Moved old zlib files to netgraph/ng_zlib and made all ng_zlib functions static.

PROBE6 for cryptodeflate.

Cosmetic changes.

Removed ifndef in zlib, stopped using -DNO_GZIP, and removed opensolaris/.../zmod

libkern/kern_zlib.c to compile contrib/zlib files.

Deleted sys/sys/zutil.h

Redo svn mv sys/sys/zlib.h sys/netgraph/zlib.h.

Updating review via arc diff instead of svn diff.
Renamed sys/sys/zlib.h to sys/sys/kern_zlib.h.
Changed _KERNEL_ to MIN for ifdef check in deflate.c.

Thank you for your feedback.

Removed some of experimental code.

Style fix.

Pick up https://svnweb.freebsd.org/base/head/sys/amd64/amd64/pmap.c?r1=329171&r2=329187

Intention of these changes were to improve reuse of code and also reduce number of locks.

vm_page_free_phys_pglist(&pgl) was removed once by a mistake.

Renamed the function and updated styles based on comments.

Removed #if 0 and added a blank line in swp_pager_launder_vmpage().

Simplify "offset" adjustments.

Adjusted styles.
Removed object argument from 2 swp_pager_*_vmpage functions

Renamed to vm_page_free_zero_pages() and it takes boolean_t to update wire count.

Call atomic_subtract_int(&vm_cnt.v_wire_count, count), too if a caller instructs so.

Replaced pmap_free_zero_pages with vm_page_free_spglist().
Fixed styles.
I will handle wire_count upon next changeset.