[Bug c++/66834] [concepts] concept parameter kind mismatch causes hard error

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66834

--- Comment #13 from Jason Merrill <jason at gcc dot gnu.org> ---
(In reply to Andrew Sutton from comment #12)
> I don't think that's a good idea. It means the template-id would be
> characterized as an atomic constraint for purposes of partial
> ordering. You lose the ability to order on constraints within the
> concept, which means you're no better off than using a type trait for
> the definition.

True, I guess it's a trade-off between power and ease of use.  Should I
re-apply the change to coerce_template_parms?