[Bug other/51174] AIX unexpected error_mark node in new TM tests

[dje at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51174

--- Comment #12 from David Edelsohn <dje at gcc dot gnu.org> 2011-11-18 18:20:50 UTC ---
Your patch will fix the problem, but, as I wrote in comment 10, I think it is
wrong.  I guess you can change the semantics of tm_mangle() to return NULL for
NULL argument, but it covers up potential bugs.  tm_mangle() should not be
called with NULL argument and any caller that does should be fixed.