(rx (| ,(rx numeric) ,(rx alphabetic))) doesn't:, even
though the "type-checking rules" for char-sets says
that it should:
> (rx (| numeric alphabetic))
'#{re-char-set}
> (rx (| ,(rx numeric) ,(rx alphabetic)))
'#{Re-choice}
The following patch fixes this but I'm not sure if
make-re-choice is the right place to tackle this problem:
This fixes bug report #1063781