tests for flower appear to miss instantiations of classes

[David Kastrup]

When configured with

./configure CXXFLAGS=-fkeep-inline-functions

(which does not optimize unused functions away)

make test fails in the flower subdirectory in the linking stage with
quite inscrutable error messages.

I don't have the error message handy right now, but since this has been
bugging me on and off for at least a month (basically the only thing
failing with make check for me) and I have not been able to make any
progress on figuring out just what to do (spent about a day on it), I
decided to report this before I forget again.

-- 
David Kastrup