Subzero: Reduce copying of Liveness bitvectors.

src/IceCfgNode.h

Index: src/IceCfgNode.h
diff --git a/src/IceCfgNode.h b/src/IceCfgNode.h
index f7e7b0e20ee07e190a13a94901874682ba04a85e..ca95afb2108dd3e3c48062bd6d38d8ab9c41139b 100644
--- a/src/IceCfgNode.h
+++ b/src/IceCfgNode.h
@@ -99,7 +99,7 @@ public:
   void doNopInsertion(RandomNumberGenerator &RNG);
   void genCode();
   void livenessLightweight();
-  bool liveness(Liveness *Liveness);
+  bool liveness(Liveness *Liveness, LivenessBV *ScratchBV);
   void livenessAddIntervals(Liveness *Liveness, InstNumberT FirstInstNum,
                             InstNumberT LastInstNum);
   void contractIfEmpty();