[llvm] [Coroutines] Make CoroSplit properly update CallGraph (PR #107935)

[Chuanqi Xu via llvm-commits]

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@@ -2080,12 +2080,13 @@ splitCoroutine(Function &F, SmallVectorImpl<Function *> &Clones,
   return Shape;
 }
 
-static void updateCallGraphAfterCoroutineSplit(
+static LazyCallGraph::SCC &updateCallGraphAfterCoroutineSplit(
     LazyCallGraph::Node &N, const coro::Shape &Shape,
     const SmallVectorImpl<Function *> &Clones, LazyCallGraph::SCC &C,
     LazyCallGraph &CG, CGSCCAnalysisManager &AM, CGSCCUpdateResult &UR,
     FunctionAnalysisManager &FAM) {
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ChuanqiXu9 wrote:

nit: the signature is slightly odd to me. It looks better to make it the below `CurrentSCC` to be an output parameter of the function. So that we can avoid the odd the pattern

https://github.com/llvm/llvm-project/pull/107935