[RISCV][GISEL] Remove unused LegalizerHelper argument from legalizeExtractSubvector. NFC.

This argument was leftover from a draft version of the patch that added it.

Author: michaelmaitland

llvm/lib/Target/RISCV/GISel/RISCVLegalizerInfo.cpp

@@ -965,7 +965,6 @@ static LLT getLMUL1Ty(LLT VecTy) {
 }
 
 bool RISCVLegalizerInfo::legalizeExtractSubvector(MachineInstr &MI,
-                                                  LegalizerHelper &Helper,
                                                   MachineIRBuilder &MIB) const {
   GExtractSubvector &ES = cast<GExtractSubvector>(MI);
 
@@ -1126,7 +1125,7 @@ bool RISCVLegalizerInfo::legalizeCustom(
   case TargetOpcode::G_SPLAT_VECTOR:
     return legalizeSplatVector(MI, MIRBuilder);
   case TargetOpcode::G_EXTRACT_SUBVECTOR:
-    return legalizeExtractSubvector(MI, Helper, MIRBuilder);
+    return legalizeExtractSubvector(MI, MIRBuilder);
   case TargetOpcode::G_LOAD:
   case TargetOpcode::G_STORE:
     return legalizeLoadStore(MI, Helper, MIRBuilder);

llvm/lib/Target/RISCV/GISel/RISCVLegalizerInfo.h

@@ -46,8 +46,7 @@ class RISCVLegalizerInfo : public LegalizerInfo {
   bool legalizeVScale(MachineInstr &MI, MachineIRBuilder &MIB) const;
   bool legalizeExt(MachineInstr &MI, MachineIRBuilder &MIRBuilder) const;
   bool legalizeSplatVector(MachineInstr &MI, MachineIRBuilder &MIB) const;
-  bool legalizeExtractSubvector(MachineInstr &MI, LegalizerHelper &Helper,
-                                MachineIRBuilder &MIB) const;
+  bool legalizeExtractSubvector(MachineInstr &MI, MachineIRBuilder &MIB) const;
   bool legalizeLoadStore(MachineInstr &MI, LegalizerHelper &Helper,
                          MachineIRBuilder &MIB) const;
 };