c++/3598: more virtual inheritance ctor problems

[scott snyder]

hi -

I just wanted to add that last night i managed to find a workaround
for this problem.  If i ensure that all the classes in the hierarchy
have at least one data member, then the problem goes away.

If i go back to the application i was originally trying to build
and do the same thing there, i can get it to execute correctly.
Yay!  So this problem is no longer so urgent for me.

sss