7b9a7ef218
Erase regions in New Abstract Consts When an abstract const is constructed, we previously included lifetimes in the set of substitutes, so it was not able to unify two abstract consts if their lifetimes did not match but the values did, despite the values not depending on the lifetimes. This caused code that should have compiled to not compile. Fixes #98452 r? ```@lcnr```