[Bug middle-end/70861] Improve code generation of switch tables

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70861

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note I think if we had gotos instead of assignment here we should do the
similar thing for the switch table itself.

Note also the assignment to i is getting in the way for the switch to constant
table form.