[Bug middle-end/89091] ICE: Segmentation fault (in tree_class_check)

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89091

--- Comment #6 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Created attachment 45774
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45774&action=edit
Patch

I came up with this patch; it survives bootstrap&regrtesting, but am not sure
if it's correct.