Revision 424237

Since base r283461 /compat/linux/dev/shm must point to a tmpfs.  Make
/compat/linux/dev/shm a plain directory instead of a link to /tmp so we
don't force users to mount tmpfs on /tmp.  This also makes /dev/shm a
separate namespace from /tmp.

Add libffi, needed by glib2.

PR:		207769