[llvm] [CodeGen][NewPM] Port "PostRAMachineSink" pass to NPM (PR #129690)

[Matt Arsenault via llvm-commits]

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@@ -2390,7 +2390,5 @@ PostRAMachineSinkingPass::run(MachineFunction &MF,
   if (!PostRAMachineSinkingImpl().run(MF))
     return PreservedAnalyses::all();
 
-  auto PA = getMachineFunctionPassPreservedAnalyses();
-  PA.preserveSet<CFGAnalyses>();
-  return PA;
+  return getMachineFunctionPassPreservedAnalyses().preserveSet<CFGAnalyses>();
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arsenm wrote:

I'd rather just keep the temporary variable (with no auto too) 

https://github.com/llvm/llvm-project/pull/129690