OPT_LTDominatorInfo info = (OPT_LTDominatorInfo)b.scratchObject;
  private void addNode(OPT_BasicBlock b) {    OPT_LTDominatorInfo info = (OPT_LTDominatorInfo)b.scratchObject;    OPT_DominatorTreeNode node = new OPT_DominatorTreeNode(b);    dominatorInfoMap[b.getNumber()] = node;  }