[tree-ssa] CCP and non-destructive folding problems

[law@redhat.com]

In message <1046304111.1114.32.camel@frodo>, Diego Novillo writes:
 >> A general note -- from looking at your patches it appeared that you were
 >> trying to get the two folders to always return the same results.  That's
 >> not a particularly interesting thing to do.
 >> 
 >>   The (poorly named) nondestructive folder is used for constant discovery,
 >>   and as a result stuff like simplifying var + 0 to var isn't really
 >>   interesting.
 >> 
 >Yes.  I got caught by this.  I see now that you had something else in
 >mind for the nd-folder.  Maybe it would make sense to rename it or
 >simply document its intended use?
I think I'll end up re-naming it and updating its comments to more
clearly indicate it's intended purpose.  I caught myself a couple times
making the same mistake :-)

jeff