too much GCSE on ia64

[Paolo Bonzini]

Brad, thanks for your analysis -- it's right, I have loads of computed
gotos that implement prefetching and predecoding in order to take
advantage of branch registers on the ia64.

I agree that reloading everything is correct.  But, the very idea of
having sixty or so common subexpressions that are as simple as `x+8',
`x+24' and so on is overzealous in my opinion.  GCC cannot know that my
caches are reloaded about once every five bytecodes, but the behavior is
strange nevertheless.

Paolo