VMS jam porting: remove exception call when file_dirscan()
can't, for some reason, scan a directory. Use a better
set of #ifdefs to determine if we're on a vax, rather than
relying on the C compiler being a specific version: we're
able to build with the C++ compiler now.
=== computer.perforce.com:1666: Change 21441 by PERFORCE@vulgar on 2001/03/23 12:17:15