[llvm] [CodeGenPrepare][NPM] Remove incorrect LoopAnalysis preservation in CodeGenPrepare (PR #172418)

[Christudasan Devadasan via llvm-commits]

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@@ -556,7 +556,6 @@ PreservedAnalyses CodeGenPreparePass::run(Function &F,
   PreservedAnalyses PA;
   PA.preserve<TargetLibraryAnalysis>();
   PA.preserve<TargetIRAnalysis>();
-  PA.preserve<LoopAnalysis>();
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cdevadas wrote:

This pass doesn't preserve anything if run for the legacy pipeline. I wonder why we preserve the other analyses only for NPM?

https://github.com/llvm/llvm-project/pull/172418