-fcse-follow-jumps and -fcse-skip-blocks and GCSE

[Richard Kenner]

When I added those two options to CSE, we knew they shouldn't be needed
once a global CSE was written.  Well, we have one now and they are still
there.  Are they needed?

Can somebody volunteer to do some benchmarking with those options on
and off (note they default on in -O2) and see if they really help?

If so, we need to find out why since they are expensive and should
be deleted.