[RFA/hppa] Fix pb in inferior function call

[Andrew Cagney]

> I think one of the previous dummy call mechanisms wasn't
> supposed to:
>   if (DEPRECATED_DUMMY_WRITE_SP_P ())
>     DEPRECATED_DUMMY_WRITE_SP (sp);

It was never really pinned down, either using write_sp or using 
push_dummy_args (or what ever it was called), or ...

Now push_dummy_call is responsible for everything.

> so it probably just got lost in a conversion.

Yes.

Joel, do you think a pull up of the hppa stuff onto the 6.1 branch would 
be useful?  (it can only break HP/UX so is "mostly harmless").

Andrew