reload vs adds with clobbers

[DJ Delorie]

> We're having the same problem on s390.

Thanks, I'll look and see what you've done.

> The way I've fixed it is to prevent gen_reload from ever taking that
> path by marking all PLUS expressions that would otherwise go there
> as needing a secondary reload (via SECONDARY_INPUT_RELOAD_CLASS) and
> doing the right thing in reload_insi ...

There's got to be a better way to handle this situation.  Why can't
reload just use the right expander?