[SystemZ] Improve handling of SETCC

We previously used the default expansion to SELECT_CC, which in turn would
expand to "LHI; BRC; LHI".  In most cases it's better to use an IPM-based
sequence instead.

llvm-svn: 192784
diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.h b/llvm/lib/Target/SystemZ/SystemZISelLowering.h
index 3f272c3..820b680 100644
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.h
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.h
@@ -252,6 +252,7 @@
   const SystemZTargetMachine &TM;
 
   // Implement LowerOperation for individual opcodes.
+  SDValue lowerSETCC(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerGlobalAddress(GlobalAddressSDNode *Node,