Include Makefiles under sys/arch.

This makes it easy to install the set of kernel headers that were used
by buildrump.sh.  Requested by Justin Cormack for ljsyscall (Lua interface
definitions).
include namespace.h - this fixes 48091
Add fchownat(2) specific errors.
Add extern int psratio
Add mkfifoat(2) specific errors.
Add mknodat(2) specific errors.
Mark the dead.
Don't pass assembler flags to cpp for genassym.
Don't depend on implicit rounding from non-integral float constant.
Strip redundant parenthesis.
`makefs -t cd9660' fix from FreeBSD:
Submitted by:   Thomas Schmitt via marius@freebsd.org
Obtained from:  FreeBSD r253707

- Correctly set the Expiration Time in the Primary Volume Descriptor;
  according to ISO 9660 8.4.26.1 unspecified date and time are denoted by the
  digit 0 in RBP 1 to 16 but the number 0 in RBP 17.

- Rock Ridge TF entries should use a length of 5, because after the 4 bytes of
  generic SUSP header there is one byte of flags. See typedef of ISO_RRIP_TF
  in iso9660_rrip.h.
Add a new get_utimens32() helper function that fetch struct timespec
data if not NULL, to be used by netbsd32_utimensat() and
netbsd32_futimens().
Decide ET_DYN behavior based on __GLIBC__ instead of __linux__,
e.g. musl libc doesn't follow glibc behavior.

per discussions with a number of people
comment polish: just musl
Allow an empty .MAKE.JOB.PREFIX to supress output of --- job --- tokens
avoid uninitialized use of defattr
sanity check uboot_args is within 512MB (not 256MB) for beaglebone black).
Fixing debug set lists for bind. Tested on amd64, testing on evbarm.
Actually, only copy the uboot args if they are within the amount of ram we
mapped.  If they aren't we'd fault trying to access them.  It's too early
to grab a VA to map them so we just punt for now. XXX
Store local bindings in a rbtree