[M3commit] CVS Update: cm3

[Antony Hosking]

CVSROOT:	/usr/cvs
Changes by:	hosking at birch.	07/06/28 16:52:00

Modified files:
	cm3/m3-libs/m3core/src/thread/POSIX/: ThreadPosix.m3 

Log message:
	Make sure that ProcessStacks does not trigger GC barriers by using LOOPHOLE to
	perform untraced accesses to the heap.  This is safe because we know that
	ProcessStacks runs when the collector is already on, thread-switching is
	disabled, and objects are not yet moving.