* There is no reason for SpillWeights to be an instance var

* There is no reason for SpillWeights to be an instance var
* Do not put fixed registers into the unhandled set.  This means they will
  never find their way into the inactive, active, or handled sets, so we
  can simplify a bunch of code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17945 91177308-0d34-0410-b5e6-96231b3b80d8