stage1: Fix comparison of unions containing zero-sized types
The code tried to be too smart and skipped the equality (returning true)
if the payload type was zero-sized.
This optimization is completely wrong when the union payload is a
metatype!
Fixes #7047
85665386c6LemonBoy committed on 11/10/2020, 10:24:41 PM· committed by Andrew Kelleyparent2c0caa8