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

llvm-svn: 367633
diff --git a/llvm/lib/CodeGen/MIRPrinter.cpp b/llvm/lib/CodeGen/MIRPrinter.cpp
index 0a95a0c..e6010c9 100644
--- a/llvm/lib/CodeGen/MIRPrinter.cpp
+++ b/llvm/lib/CodeGen/MIRPrinter.cpp
@@ -290,7 +290,7 @@
 
   // Print the virtual register definitions.
   for (unsigned I = 0, E = RegInfo.getNumVirtRegs(); I < E; ++I) {
-    unsigned Reg = TargetRegisterInfo::index2VirtReg(I);
+    unsigned Reg = Register::index2VirtReg(I);
     yaml::VirtualRegisterDefinition VReg;
     VReg.ID = I;
     if (RegInfo.getVRegName(Reg) != "")