[ARC] Fix -Wunused-variable. NFC

Author: MaskRay

llvm/lib/Target/ARC/ARCInstrInfo.cpp

@@ -44,8 +44,7 @@ enum TSFlagsConstants {
 void ARCInstrInfo::anchor() {}
 
 ARCInstrInfo::ARCInstrInfo(const ARCSubtarget &ST)
-    : ARCGenInstrInfo(ARC::ADJCALLSTACKDOWN, ARC::ADJCALLSTACKUP), ST(ST),
-      RI(ST) {}
+    : ARCGenInstrInfo(ARC::ADJCALLSTACKDOWN, ARC::ADJCALLSTACKUP), RI(ST) {}
 
 static bool isZeroImm(const MachineOperand &Op) {
   return Op.isImm() && Op.getImm() == 0;

llvm/lib/Target/ARC/ARCInstrInfo.h

@@ -24,7 +24,6 @@ namespace llvm {
 class ARCSubtarget;
 
 class ARCInstrInfo : public ARCGenInstrInfo {
-  const ARCSubtarget &ST;
   const ARCRegisterInfo RI;
   virtual void anchor();