bsd.progs.mk must pass META_XTRAS to gendirdeps.mk

The indirection used by bsd.progs.mk is setting META_XTRAS
means the value needs to be passed in the environment to
gendirdeps.mk, as any expansion before then will be empty.

Remove a now misleading comment from bsd.progs.mk
before it includes bsd.prog.mk

Update gendirdeps.mk to accommodate this.

Reviewed by: stevek

Update meta.sys.mk and related local*mk

Move the setting of TARGET_SPEC_VARS to local.sys.env.mk
so meta.sys.mk can do the processing, and include local.meta.sys.mk
later.

Move the setting of GENDIRDEPS_FILTER*_VARS from local.gendirdeps.mk
to local.meta.sys.mk so we can automatically set DEP_* at level 1+
to avoid syntax errors when DEP_* variables are used in conditionals
in Makefile.depend files.

Update gendirdeps.mk just to get the documentation about the above.
No functional change.

local.dirdeps.mk be more careful about adding to DIRDEPS to avoid
unnecessary overhead, and introducing cycles in the graph.
Also set DEP_MACHINE_CPUARCH.

Reviewed by: stevek
Sponsored by: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D39737

Update meta mode makefiles

meta2deps - add checks to detect truncated/corrupted filemon data
(only known to happen on Linux hosts), to ensure we do not auto
update dependencies based on incomplete data.

meta.stage.mk adds STAGE_SHLIB_LINKS_FILTER and STAGE_LINK_AS_*

We also allow for hosts where egrep is deprecated for grep -E

Reviewed by: stevek

Update dirdeps.mk et al to latest

Move some local tweaks to local.*.mk

Reviewed by: bdrewery
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D27300

Update dirdeps.mk and gendirdeps.mk

The env space consumed by exporting all libc's .meta files
left little room for command line,
so unexport when done.

Update dirdeps.mk to latest and add
dirdeps-targets.mk to simplify/update targets/Makefile

Makefile changes to go with Makefile.depend changes in D22494

Reviewed by: bdrewery
MFC after: 1 week
Sponsored by: Juniper Networks
Differential Revision: https://reviews.freebsd.org/D22495

Update dirdeps.mk et al to latest

dirdeps.mk and meta.autodep.mk will now look for
Makefile.depend.options
to handle optional dependencies, the work is all done by
dirdeps-options.mk

Also update to latest meta.stage.mk and gendirdeps.mk

Reviewed by: bdrewery
Differential Revision: https://reviews.freebsd.org/D15701

Update meta* from bmake-20161212

Update dirdeps.mk et al

dirdeps.mk: move logic to handle -f dirdeps.mk to inside check
for first read of dirdeps.mk

Also fix handling of WITHOUT_DIRDEPS_BELOW

gendirdeps.mk: pass M2D_EXCLUDES to meta2deps

meta.autodep.mk: if we build with nofilemon, leave a cookie to
prevent updating dependencies until cleaned.

Reviewed by: bdrewery

Import latest gendirdeps.mk 1.29 from contrib/bmake/mk

Latest dirdeps.mk sets DEP_RELDIR for itself.

This helps guard against bugs in manually edited Makefile.depend
files, and avoids the need to call realpath from the Makefile.depend file.

Update to latest versions.

Bring meta2deps.sh closer to par with meta2deps.py

If TARGET_OBJ_SPEC is no just MACHINE, pass it to meta2deps.py

Sync latest versions

When processing DPADD, defer application of :tA (realpath)
so we do not lose /.

Revert the dance for skipping machine qualified dependfile.
We just note when using non-machine qualified dependfile for "host"
and skip update.

Make sure we qualify _objroot with trailing / if needed

If .MAKE.DEPENDFILE_DEFAULT is not machine qualified, and we
find oursleves creating a machine qualified .MAKE.DEPENDFILE which
is identical to a default which exists - skip it.

This allows us to create Makefile.depend.host where it matters,
while leveraging Makefile.depend where it is sufficient.

Handle multiple M2D_OBJROOTS better

Latest *dirdeps.mk and meta2deps

Sync FreeBSD's bmake branch with Juniper's internal bmake branch.

Requested by: Simon Gerraty <sjg@juniper.net>