although one tactic not yet implemented, but soon ..., is to make struct and union alignment

match the least alignment required, as is done for arrays, the approach on amd64 and arm64

is simply not to bother with the unions. if it's sp, it's sp. link is link. i think the need for the alias

has gone. there aren't any references in port, which i think might have caused the aliasing

in the first place, and xyz/trap.c should know what's what.