(toplevel) Fix dramatic breakage for ordinary crosses (related to program_transform_name)

[Michael Elizabeth Chastain]

My two cents:

To me, a race is a race.  Just don't have them in the first place and no
bugs will creep in.

I would also prefer no locks, because I don't want to deal with locking
mechanism headaches when a user with, say, an SMP Irix NFS client and
an HP/UX NFS server has funny build problems.

So I'm in favor of a dumb, simple, and reliable mechanism to serialize
the configures.

Michael C