[Pipelines] Move SimplifyCFGPass in front of InstCombinePass.

[DianQK]

Summary

Fix https://github.com/llvm/llvm-project/issues/62238. Bisected to D138542.
For https://llvm.godbolt.org/z/1njhb7EYW, it is difficult for us to optimize to batter instructions after InstSimplifyPass.

I found the pipeline usually created a pair of SimplifyCFGPass + InstCombinePass. This position adjustment seems reasonable also. It's should fine to have fewer nonsense instructions before InstCombinePass.
I'm learning about the pipeline-related code for the first time and hope it hasn't affected more beneficial optimizations.

[DianQK]

Formatting code.

[nikic]

The pattern folds fine in isolation (https://alive2.llvm.org/ce/z/WfqQwW), so I don't understand why a phase ordering change would be needed for this. Most likely this just needs a special case in simplifyWithOpReplaced(), to say that the derefining replacement is safe in this case, based on poison implication.

[DianQK]

Thanks, I understand. I will submit another patch if possible.

llvm/lib/Passes/PassBuilderPipelines.cpp

PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
   // Optimize globals to try and fold them into constants.
   MPM.addPass(GlobalOptPass());
 
   // Create a small function pass pipeline to cleanup after all the global
   // optimizations.
   FunctionPassManager GlobalCleanupPM;
   // FIXME: Should this instead by a run of SROA?
   GlobalCleanupPM.addPass(PromotePass());
+  GlobalCleanupPM.addPass(SimplifyCFGPass(SimplifyCFGOptions()
+                                              .convertSwitchRangeToICmp(true)
+                                              .hoistCommonInsts(true)
+                                              .sinkCommonInsts(true)));
   GlobalCleanupPM.addPass(InstCombinePass());
   invokePeepholeEPCallbacks(GlobalCleanupPM, Level);
-  GlobalCleanupPM.addPass(
-      SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
+
   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(GlobalCleanupPM),
                                                 PTO.EagerlyInvalidateAnalyses));
 
   // Add all the requested passes for instrumentation PGO, if requested.
   if (PGOOpt && Phase != ThinOrFullLTOPhase::ThinLTOPostLink &&
       (PGOOpt->Action == PGOOptions::IRInstr ||
        PGOOpt->Action == PGOOptions::IRUse)) {
     addPGOInstrPasses(MPM, Level,