[clang] [llvm] Revert "CodeGen: Add LibcallLoweringInfo analysis pass (#168622)" (PR #171452)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> The pass should include cost modelling, should emit hints for the vectorizer. 

No, this pass has nothing to do with cost modeling or optimization. This is a refactoring change to pull the library information out of TargetLibraryInfo



https://github.com/llvm/llvm-project/pull/171452