Silencing a warning about isZExtFree hiding an inherited virtual function. No functional change intended.

llvm-svn: 211783
diff --git a/llvm/lib/Target/R600/AMDGPUISelLowering.h b/llvm/lib/Target/R600/AMDGPUISelLowering.h
index 307921e..b7602eb 100644
--- a/llvm/lib/Target/R600/AMDGPUISelLowering.h
+++ b/llvm/lib/Target/R600/AMDGPUISelLowering.h
@@ -109,6 +109,7 @@
 
   bool isZExtFree(Type *Src, Type *Dest) const override;
   bool isZExtFree(EVT Src, EVT Dest) const override;
+  bool isZExtFree(SDValue Val, EVT VT2) const override;
 
   bool isNarrowingProfitable(EVT VT1, EVT VT2) const override;