uninteresting, just put all the operands on one list and make
GenerateReassociations make the decision about what's interesting.
This is simpler, and it avoids an extra ScalarEvolution::getAddExpr call.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111133 91177308-0d34-0410-b5e6-96231b3b80d8