Fix race condition when parallel makes compete over auditshell.o.
Fix race condition when parallel makes compete over auditshell.o.

Some versions of parallel make (Solaris x86) actually build all of their
top level targets in parallel.  When those versions of make are run in
directories with multiple top targets (e.g., backend,tools,etc.), a race
results as they compete to build, link, and delete 'auditshell.o'.  Deal
with that by creating a unique tempfile containing the auditshell's source
and, by extension, the auditshell's compiled output.

vision-dbms/vision,VCommitter/vision,VisionAerie/vision,MichaelJCaruso/vision,vision-dbms/vision,VisionAerie/vision,MichaelJCaruso/vision,VCommitter/vision,VCommitter/vision,c-kuhlman/vision,VisionAerie/vision,vision-dbms/vision,vision-dbms/vision,MichaelJCaruso/vision,VCommitter/vision,c-kuhlman/vision,c-kuhlman/vision,c-kuhlman/vision,MichaelJCaruso/vision,VCommitter/vision,MichaelJCaruso/vision,VCommitter/vision,VisionAerie/vision,VisionAerie/vision,VisionAerie/vision,MichaelJCaruso/vision,vision-dbms/vision,c-kuhlman/vision,VisionAerie/vision,vision-dbms/vision,VCommitter/vision