[Bug c++/70594] [6 Regression] -fcompare-debug failure

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70594

--- Comment #26 from Jason Merrill <jason at gcc dot gnu.org> ---
(In reply to Jason Merrill from comment #25)
> Created attachment 38245 [details]
> Patch to not discard copies
> 
> This seems like a minimal fix; does it in fact fix the bug?

With this patch gengtype seems to assign gt_ggc_mx(tree&) to cp/constexpr.o,
breaking cc1 link.  I'm not going to try to fix that now, though someone else
is welcome to.