stage2: make `error{}` the same size as `anyerror`

Having `error{}` be a zero bit type causes issues when it interracts
with empty inferred error sets which are the same size as `anyerror`.
0333ff4476Veikka Tuominen committed on 6/11/2022, 8:49:33 PMparent488e1e5
11 files changedLine totals unavailable