[Bug target/81357] Extra mov for zero extend of add

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81357

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
-O1 produces an extra zero extend.
-O2 and above produces an extra move instruction.

The zero extend is not needed as the add does an implicit zero extend already.