vm: fix sanity checks on arm

The 'polarity' of the RW bit is inversed on ARM, causing one
of the sanity check compensations to fail. ARM now runs basic
stuff with sanity checks passing.

Change-Id: Iee28ab63e430e759f204eeb204b24c301d5ea3c9
Upgrading ls

Change-Id: Ie0bacf04e727fac5c6df7b2bcf5039e9ce800616
Upgrading sync

Change-Id: Ied34ebd1d2dc963f5a2af8fc3bbf8e6c94df61cf
Fix warning about double rule for rc in ramdisk

Change-Id: I870364455e5cbfe178b3dba44a1c944ca7ed9d19
kernel: scheduling fix for ARM

	. make read_tsc_64 use the free-running clock, significantly
	  improving scheduling behaviour

Change-Id: Idf6a12f6e26be7fe3b3664c278cae846d8b2a442
umount: getopt return value is int, not char

	. causes infinite loop on ARM (default unsigned char?)

Change-Id: If00184f37317c8597a8203f68ec96f1ce5030853
kernel, libc: signals fixes

	. kernel: signal handler args for ARM
	. kernel: sanity check return address (LSB indicates thumb mode)
	. libc: properly retrieve signal mask for ARM

together fix test37 on ARM.

Change-Id: I4e00f754c50104ed85c7fdf8ec5ad54568f20a81
libexec: detect short files

if an exec() fails partway through reading in the sections, the target
process is already gone and a defunct process remains. sanity checking
the binary beforehand helps that.

test10 mutilates binaries and exec()s them on purpose; making an exec()
fail cleanly in such cases seems like acceptable behaviour.

fixes test10 on ARM.

Change-Id: I1ed9bb200ce469d4d349073cadccad5503b2fcb0
arm: protect state after signal handler

	. set MF_CONTEXT_SET after signal handler state
	  is set so it doesn't get clobbered by the kernel
	  afterwards (i.e. by delivermsg()).

fixes at least test41.

Change-Id: I7e5e0e9311c8bbc1c0a9c7ca466ceddd9edfa03f