[SystemZ] Use SRST to implement strlen and strnlen

It would also make sense to use it for memchr; I'm working on that now.

llvm-svn: 188547
diff --git a/llvm/lib/Target/SystemZ/SystemZSelectionDAGInfo.h b/llvm/lib/Target/SystemZ/SystemZSelectionDAGInfo.h
index 123cb63..26d6488 100644
--- a/llvm/lib/Target/SystemZ/SystemZSelectionDAGInfo.h
+++ b/llvm/lib/Target/SystemZ/SystemZSelectionDAGInfo.h
@@ -58,6 +58,16 @@
                           SDValue Src1, SDValue Src2,
                           MachinePointerInfo Op1PtrInfo,
                           MachinePointerInfo Op2PtrInfo) const LLVM_OVERRIDE;
+
+  virtual std::pair<SDValue, SDValue>
+  EmitTargetCodeForStrlen(SelectionDAG &DAG, SDLoc DL, SDValue Chain,
+                          SDValue Src, MachinePointerInfo SrcPtrInfo) const
+    LLVM_OVERRIDE;
+
+  virtual std::pair<SDValue, SDValue>
+  EmitTargetCodeForStrnlen(SelectionDAG &DAG, SDLoc DL, SDValue Chain,
+                           SDValue Src, SDValue MaxLength,
+                           MachinePointerInfo SrcPtrInfo) const LLVM_OVERRIDE;
 };
 
 }