MIsched machine model: tablegen subtarget emitter improvement.

Fix the way resources are counted. I'm taking some time to cleanup the
way MachineScheduler handles in-order machine resources. Eventually
we'll need more PPC/Atom test cases in tree.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176390 91177308-0d34-0410-b5e6-96231b3b80d8