[llvm] [LTO][Pipelines][Coro] Handle coroutines in LTO pipeline (PR #126168)

[Arthur Eubanks via llvm-commits]

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@@ -1983,7 +1988,11 @@ PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level,
 
   // If we didn't decide to inline a function, check to see if we can
   // transform it to pass arguments by value instead of by reference.
-  MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(ArgumentPromotionPass()));
+  CGSCCPassManager CGPM;
+  CGPM.addPass(ArgumentPromotionPass());
+  CGPM.addPass(CoroSplitPass(Level != OptimizationLevel::O0));
+  CGPM.addPass(CoroAnnotationElidePass());
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aeubanks wrote:

compile-time-wise, it shouldn't matter. CoroConditionalWrapper was added to preventing having to construct the LazyCallGraph just to throw it away immediately, but that's not relevant here. AFAIK the coroutine passes all bail early if there aren't any coroutine intrinsics

https://github.com/llvm/llvm-project/pull/126168