[Bug c++/57678] too many errors for bad template parameter

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57678

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I think this is due to once a undeclared decl has been found, its type becomes
int which I think is just wrong.  We should use error_mark_node and then handle
the fall out from there.

There have been a few bugs with errors like this which points to the same issue
of treating undeclared decls as ints.