Remove liveout lists from MachineRegisterInfo.

All targets are now adding return value registers as implicit uses on
return instructions, and there is no longer a need for the live out
lists.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174417 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index d8b5fd4..32d0668 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -1515,12 +1515,12 @@
       unsigned Reg = MO.getReg();
       if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
         const MachineRegisterInfo &MRI = MF->getRegInfo();
-        if (MRI.use_empty(Reg) && !MRI.isLiveOut(Reg)) {
+        if (MRI.use_empty(Reg)) {
           bool HasAliasLive = false;
           for (MCRegAliasIterator AI(Reg, TM->getRegisterInfo(), true);
                AI.isValid(); ++AI) {
             unsigned AliasReg = *AI;
-            if (!MRI.use_empty(AliasReg) || MRI.isLiveOut(AliasReg)) {
+            if (!MRI.use_empty(AliasReg)) {
               HasAliasLive = true;
               break;
             }