FreeBSD, autom4te and locking on NFS

[Ralf Wildenhues]

Invocation of autom4te fails currently on FreeBSD with NFS-mounted
directories:
| ../build-alpha-unknown-freebsd6.0/tests/autoconf
| autom4te: cannot lock autom4te.cache/requests with mode 2 (perhaps you are 
running make -j on a lame NFS client?): Operation not supported

Of course, this prevents any successful autoconf runs, and thus causes
massive testsuite failure.  It'd be great if somebody more fluent with
perl and locking issues look into this and debug the respective lock
method in lib/Autom4te/XFile.pm.

Seen on the HP testdrive hosts, with
| This is perl, v5.8.6 built for alpha-freebsd

Cheers,
Ralf