[llvm] [PassBuilder] Add a pass to LTO postlink step (PR #124053)

[via llvm-commits]

================
@@ -1926,6 +1926,8 @@ PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level,
   // Remove unused arguments from functions.
   MPM.addPass(DeadArgumentEliminationPass());
 
+  MPM.addPass(RelLookupTableConverterPass());
----------------
gulfemsavrun wrote:

I moved the pass later in the LTO pipeline. The early return for other optimization levels are for `-O0` and `-O1`, and I think it is reasonable to add this pass when built with `-O2` and higher.

https://github.com/llvm/llvm-project/pull/124053