Hello,

This is trying to fix 
http://sources.redhat.com/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gdb&pr=656

It breaks the host system down into:

- realpath() and constant pathmax

- canonicalize file name

- realpath() and pathconf()

- xstrdup()

realpath() is split into two cases - the easy / common one and the nasty 
horrible pathconf() one.  The latter (which was causing grief on GNU) 
has been moved to the end.

comments?  For 5.3 and mainline.

Andrew