Finish moving TargetRegisterInfo::isVirtualRegister() and friends to llvm::Register as started by r367614. NFC

llvm-svn: 367633
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp b/llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
index 3851ee8..b2491eb 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
@@ -544,7 +544,7 @@
   if (!N->isMachineOpcode()) {
     if (N->getOpcode() == ISD::CopyToReg) {
       unsigned Reg = cast<RegisterSDNode>(N->getOperand(1))->getReg();
-      if (TargetRegisterInfo::isVirtualRegister(Reg)) {
+      if (Register::isVirtualRegister(Reg)) {
         MachineRegisterInfo &MRI = CurDAG->getMachineFunction().getRegInfo();
         return MRI.getRegClass(Reg);
       }