RE: new mul* patterns "U" constraint in rl78

[Kaushik Phatak]

>> +;;  [(set_attr "valloc" "umul")]
>I think this one needs to be macax also, since the constraints have "v" in 
>them but the opcodes use ax.
> Other than that, it's OK.

Committed with above change.

Thanks for the quick review.

Regards,
Kaushik