[clang] [CIR] Implement FlattenCFG for coroutine AwaitOp, CoroBodyOp, and CoReturnOp (PR #203802)

[via cfe-commits]

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@@ -2110,12 +2118,339 @@ class CIRTryOpFlattening : public mlir::OpRewritePattern<cir::TryOp> {
   }
 };
 
+static void
+collectCoReturnsOps(mlir::Region &region,
+                    llvm::SmallVectorImpl<cir::CoReturnOp> &coReturnOps) {
+  region.walk(
+      [&](cir::CoReturnOp coReturnOp) { coReturnOps.push_back(coReturnOp); });
+}
+
+// Flatten `cir.coroutine`. It runs once every nested op (awaits, scopes,
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Andres-Salamanca wrote:

Done.

https://github.com/llvm/llvm-project/pull/203802