Add variations on: max(x,y) >= min(x,z) folds to true. This isn't that common,

but according to my super-optimizer there are only two missed simplifications
of -instsimplify kind when compiling bzip2, and this is one of them.  It amuses
me to have bzip2 be perfectly optimized as far as instsimplify goes!

llvm-svn: 130840