[clang] [ClangIR] Support bool-returning await_suspend (PR #227527)

[Aman Maurya via cfe-commits]

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@@ -662,16 +662,21 @@ emitSuspendExpression(CIRGenFunction &cgf, CGCoroData &coro,
         // and coro.suspend here, that should be done as part of lowering this
         // to LLVM dialect (or some other MLIR dialect)
 
-        // A invalid suspendRet indicates "void returning await_suspend"
-        mlir::Value suspendRet = cgf.emitScalarExpr(s.getSuspendExpr());
-
-        // Veto suspension if requested by bool returning await_suspend.
-        if (suspendRet) {
-          cgf.cgm.errorNYI("Veto await_suspend");
+        if (s.getSuspendReturnType() ==
+            CoroutineSuspendExpr::SuspendReturnType::SuspendBool) {
+          mlir::Value suspendRet = cgf.evaluateExprAsBool(s.getSuspendExpr());
+          // Veto suspension if requested by bool returning await_suspend.
+          builder.createCondition(suspendRet);
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amanmaurya92 wrote:

@bcardosolopes and @Andres-Salamanca I implemented the suggested `cir.coro.suspend_point(%cond)` design

https://github.com/llvm/llvm-project/pull/227527