[llvm] [Hexagon] Use LiveRegUnits (PR #84112)

[Krzysztof Parzyszek via llvm-commits]

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@@ -346,11 +346,11 @@ bool HexagonGenMux::genMuxInBlock(MachineBasicBlock &B) {
 
   // Fix up kill flags.
 
-  LivePhysRegs LPR(*HRI);
+  LiveRegUnits LPR(*HRI);
   LPR.addLiveOuts(B);
   auto IsLive = [&LPR, this](unsigned Reg) -> bool {
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kparzysz wrote:

With this change, just replace `IsLive` with `LPR.available`.

https://github.com/llvm/llvm-project/pull/84112