This patch adds FIXED_CST to copy_reference_ops_from_ref in
tree-ssa-sccvn.c. Some test code (using fixed-point constants) failed
for me without it. This looks obvious to me, unless there's some
particular reason fixed-point constants need to be handled differently
(or not at all) in that function.

Tested alongside other patches in the series. OK to apply?

Julian

ChangeLog

    gcc/
    * tree-ssa-sccvn.c (copy_reference_ops_from_ref): Support FIXED_CST.