MFC r314651,r318439,r318440:

r314651:

sys/modules: normalize .CURDIR-relative paths to SRCTOP

This simplifies make output/logic

Tested with: `cd sys/modules; make ALL_MODULES=` on amd64

r318439:

Normalize .PATH on SRCTOP

This will help Jenkins dedupe 9 warnings between the static build and
the module build of ipsec(4).

Missed in SRCTOP conversion in r314651.

MFC with: r314651

r318440:

Normalize SYSDIR on SRCTOP instead of .CURDIR

This is being done to simplify pathing for CFLAGS and source files.

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

Back out previous commits. Installing new share/mk fixes this.

NO_MAN is now NOMAN.

Fix kernel modules build. For some reason, this module now bails out with
an error that there is no aicasm.1 man page.

Hook the aic7xxx modules up. This requires some extra care since aicasm
is a compiler tool and needs to be compiled by the host compiler. I've
tested this in i386->sparc cross-build, 4.7->current upgrade, normal
buildkernel target, and normal /sys/i386/compile/GENERIC configurations.

Submitted by: ru

Add cleandepend target.

Pass the cleandir target on to the aicasm Makefile. This should
fix the buildkernel target.

Complete the hookup of ahd/ahc module building.

Allow the ahc and ahd drivers to be built as modules. This also
breaks the ahc driver into a core back-end and pci and eisa
front-ends.