file. The temporary file code can be reenabled by building with
-DDIRS_USE_FILE.
Fixes a problem where sysinst would fail to unpack the base set because
the temporary file wouldn't fit in the ramdisk.
Continue partial write(2) on signals (xwrite()).
Partial read(2) at a few places are also continued (xread()).
Add {read,write}_with_restart() hooks for porting on systems
which don't restart interrupted read()/write() calls.
Reviewed and discussed in tech-kern and tech-userlevel lists.