[ping] Ignore thread local symbols when generating dbx debug

[John David Anglin]

> 2008-03-04  James E. Wilson  <wilson@tuliptree.org>
> 
> 	* dbxout.c (dbxout_expand_expr, case VAR_DECL): Return NULL for
> 	emulated thread local variables.

This change also works.  It eliminates all the emulated TLS failures
in the libgomp testsuite on hppa2.0w-hp-hpux11* and I didn't see any
new regressions related to the change.

Thanks,
Dave
-- 
J. David Anglin                                  dave.anglin@nrc-cnrc.gc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6602)