MFC r345839, r345894, r345897, r345900-r345901, r345976, r346220, r348602, r348767, r348967,
r349047-r349048, r351204-r351205, r351502, r351623, r352364, r356249-r356250, r356313,
r356434, r356628-r356629, r356636, r356657, r357421, r357716, r360359, r360428:

r345839: Assert that q can't be NULL. 'empty' is always non-NULL when DIREMPTY
r345894: Restore the ability of checking and fixing next free
r345897: Restore lfcl when LOSTDIR's chain was corrupted and overwritten
r345900: Implement checking of `.' and `..' entries of subdirectory.
r345901: Fix build.
r345976: Write string constant differently to improve readability.
r346220: Don't cast result from malloc().
r348602: Don't increment cl after increment.
r348767: preen should work independently with alwaysyes and alwaysno.
r348967: Avoid out of boundary access when checking invalid long filenames.
r349047: Blankspace. No actual code change.
r349048: In ask(): override default option if any of alwaysyes/alwaysno/rdonly is
r351204: Remove redundant check and wrong fix: fat.c checks already take care
r351205: Use calloc().
r351502: Comment boot block checks and perform additional sanity checks:
r351623: Remove unneeded blank line. No functional change.
r352364: Avoid mixing cluster numbers and sector numbers. Makes code more readable.
r356249: Reduce memory footprint of fsck_msdosfs.
r356250: Revert r356249 for now as it broke GCC builds.
r356313: Reduce memory footprint of fsck_msdosfs.
r356434: fsck_msdosfs.8: document -M.
r356628: Require FAT to occupy at least one sector.
r356629: Apply typo fix from NetBSD, we have already applied all NetBSD changes so
r356636: Correct off-by-two issue when determining FAT type.
r356657: Tighten FAT checks and fix off-by-one error in corner case.
r357421: Diff reduction against NetBSD, no functional change.
r357716: Use humanize_number to format available and bad space sizes.
r360359: Fix a bug with dirty file system handling.
r360428: Do not overflow when calculating file system size.

MFC r314655:

bin: normalize paths using SRCTOP-relative paths or :H when possible

This simplifies make logic/output

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Merge the projects/release-pkg branch to head.

This allows packaging the base system with pkg(8), including
but not limited to providing the ability to provide upstream
binary update possibilities for non-tier-1 architectures.

This merge is a requirement of the 11.0-RELEASE, and as such,
thank you to everyone that has tested the project branch.

Documentation in build(7) etc. is still somewhat sparse, but
updates to those parts will follow.

Sponsored by: The FreeBSD Foundation

Make fsck and fsck_msdosfs WARNS=6 clean

- sprinkle const
- add volatile qualifier to avoid vfork clobbering

Inspired by: NetBSD
PR: bin/139802
Reviewed by: ed

Fix some style(9), although there's a lot more issues here.
Fix some casting errors.

PR: 142384
Submitted by: giffunip at tutopia dot com
Obtained from: NetBSD
MFC after: 3 weeks

style.Makefile(5):
Use WARNS?= instead of WARNS=.

Forced commit to note that my previous commit was a Darwin merge.

Default to WARNS=2.
Binary builds that cannot handle this must explicitly set WARNS=0.

Reviewed by: mike

Style tweaks.

Add fsck_msdosfs.

Obtained from: NetBSD