[patch c++]: Fix PR 59759

[Marek Polacek]

On Tue, May 26, 2015 at 02:21:16PM +0200, Kai Tietz wrote:
> Hi,
> 
> I am not sure if suggested fix is the thing we want here.  But infact
> having here a VAR_DECL can be caused by prior errors introducing them.
> So we simply might want to treat VAR_DECL in unify via
> unify_template_argument_mismatch.
> 
> Tested for 5.x branch, and trunk.  Ok for apply?

Please add a testcase:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59759#c7

	Marek