/tmp full

[Alexy Khrabrov]

And when /tmp is not full, giving --tmpdir to top-level configure
works, but libiberty has no such option and configure freaks out.
Also, the native cc may have no -ftmpdir option, and that fails too.

Overall, usaage of TMPDIR environment variable fails, even though
AIX cc recognizes it properly.  When /tmp is full, configure can't
create here-documents and fails.  It's very instructive to fill up 
/tmp and see what configure does.

Cheers,
Alexy