[Bug bootstrap/71071] [7 regression] ICE --enable-checking=fold : fold check: original tree changed by fold

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71071

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
Calling get_alias_set cannot be avoided here, it eventually gets called via
reference_alias_ptr_type->component_uses_parent_alias_set_from.

So the solution is to excempt TYPE_ALIAS_SET from the hashing.