[LiveRegMatrix] Use MCRegUnit instead of MCRegister for register unit. NFC

MCRegister should be used for registers, not register units.

Author: topperc

llvm/include/llvm/CodeGen/LiveRegMatrix.h

@@ -161,7 +161,7 @@ class LiveRegMatrix {
   /// Use MCRegUnitIterator to enumerate all regunits in the desired PhysReg.
   /// This returns a reference to an internal Query data structure that is only
   /// valid until the next query() call.
-  LiveIntervalUnion::Query &query(const LiveRange &LR, MCRegister RegUnit);
+  LiveIntervalUnion::Query &query(const LiveRange &LR, MCRegUnit RegUnit);
 
   /// Directly access the live interval unions per regunit.
   /// This returns an array indexed by the regunit number.

llvm/lib/CodeGen/LiveRegMatrix.cpp

@@ -184,7 +184,7 @@ bool LiveRegMatrix::checkRegUnitInterference(const LiveInterval &VirtReg,
 }
 
 LiveIntervalUnion::Query &LiveRegMatrix::query(const LiveRange &LR,
-                                               MCRegister RegUnit) {
+                                               MCRegUnit RegUnit) {
   LiveIntervalUnion::Query &Q = Queries[RegUnit];
   Q.init(UserTag, LR, Matrix[RegUnit]);
   return Q;
@@ -206,7 +206,7 @@ LiveRegMatrix::checkInterference(const LiveInterval &VirtReg,
 
   // Check the matrix for virtual register interference.
   bool Interference = foreachUnit(TRI, VirtReg, PhysReg,
-                                  [&](MCRegister Unit, const LiveRange &LR) {
+                                  [&](MCRegUnit Unit, const LiveRange &LR) {
                                     return query(LR, Unit).checkInterference();
                                   });
   if (Interference)