DejaGnu PATCH to lib/dg.exp: enhance support for "exotic" dir-names

[Andrew Cagney]

GDB's main concern is that any changes made to src/dejagnu don't break
the GDB testsuite.  Have you done a before/after run of the GDB
testsuite to confirm that the results don't change?  Given you're
playing with file names, someone will probably need to check this on
both unix and cygwin.

Don't forget that anything committed to src/dejagnu and not also sent to
the official maintainer may be lost if the official dejagnu is ever
merged back into this old snapshot.

	Andrew