retire 64-bit conversion functions

Change-Id: Ib6b81403f877c363a286c654e0524fa1cb781b80
kernel, arm ucontext: ARM DBG=-g run fixes

kernel:
	. modules can be as big as the space (8MB) between them
	  instead of 4MB; memory is slightly bigger with DBG=-g

arm ucontext:
	. r4 is clobbered by the restore function, as it's
	  used as a scratch register, causing problems for the
	  DBG=-g build
	. r1-r3 are safe for scratch registers, as they are
	  caller-save, so use r3 instead; and don't bother
	  restoring r1-r3, but preserve r4

vfs:
	. improve TLL pointer sanity check a bit

Change-Id: I0e3cfc367fdc14477e40d04b5e044f288ca4cc7d
re-import makewhatis

	. to benefit from the contribution found by rjkovacic@gmail.com
	  in the minix makewhatis and submitted upstream, see NetBSD
	  PR/47958

Change-Id: I147e1afe0088ab16e7b171f74330d1c6f44a13cf
kernel: maintain stack alignment

	. 'fixes' 64-bit varargs (i.e. printf("%llu", ..)) argument
	  retrieval bug
kernel: high-hz workaround for do_settime

	. with hz=1000, clock_t only lasts a few years.
	  whenever we can't express the desired realtime
	  in ticks because the distance with boottime is
	  too high, simply adjust bootime like we do for
	  otherwise negative values.
	. fixes test 2 on ARM
test42: skip single step test

Change-Id: If57fc467b0ad28e0e9db27c6dadbe49e59dbc463