[RFA] testsuite/gdb.c++/ref-types.exp: use runto

[Michael Elizabeth Chastain]

Daniel Berlin writes:
> Um, what exactly *should* it print?

Ah, you are thinking about gdb, and I am thinking about the test suite.

As long as gdb stays the way it is, the test suite should print "FAIL".

gdb should print "20".  If it can't print "20", then it should print
"that's too hard for me" (perhaps refuse to call functions in classes with
virtual bases).

> Fine, mark them fail. Just put (Won't ever fix for v2 abi) in parentheses.

That's fine.  Then the FAIL count will reflect the actual state of the
software.

Michael