V3 PATCH: Use -rpath, not --rpath, when testing

[Benjamin Kosnik]

>     >> (I don't think we really need *everything* static; just
>     >> libstdc++ if that's easy to arrange.)
> 
>     Alexandre> It isn't, unless you break libtool's encapsulation and
>     Alexandre> look for libstdc++.a.  I don't see any value in testing
>     Alexandre> both static and shared versions; I'd rather just defer
>     Alexandre> to whatever choices the builder makes at configure time
>     Alexandre> (i.e., --enable or --disable-shared).
> 
> Talk it over with Benjamin; I've got no opinion.

No. Strangely enough, we need to test both shared and static as long as 
both are built, as sometimes the static and shared have different link 
properties. This has been an issue historically, where static binaries 
link but shared don't (say, on alpha right now, for instance) -- so we 
need this info in the "make check" rule.

-benjamin