stage2: error_set_merged type equality

This implements type equality for error sets. This is done
through element-wise error set comparison.

Inferred error sets are always distinct types and other error sets are
always sorted. See #11022.
569870ca41Mitchell Hashimoto committed on 3/10/2022, 9:20:16 PM· committed by Andrew Kelleyparent0b82c02
8 files changedLine totals unavailable