[clang] [Clang] CGCoroutines skip emitting try block for value returning `noexcept` init `await_resume` calls (PR #73160)

[Chuanqi Xu via cfe-commits]

================
@@ -129,14 +129,48 @@ static SmallString<32> buildSuspendPrefixStr(CGCoroData &Coro, AwaitKind Kind) {
   return Prefix;
 }
 
-static bool memberCallExpressionCanThrow(const Expr *E) {
-  if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
-    if (const auto *Proto =
-            CE->getMethodDecl()->getType()->getAs<FunctionProtoType>())
-      if (isNoexceptExceptionSpec(Proto->getExceptionSpecType()) &&
-          Proto->canThrow() == CT_Cannot)
-        return false;
-  return true;
+// Check if function can throw based on prototype noexcept, also works for
+// destructors which are implicitly noexcept but can be marked noexcept(false).
+static bool FunctionCanThrow(const FunctionDecl *D) {
+  const auto *Proto = D->getType()->getAs<FunctionProtoType>();
+  if (!Proto) {
+    // Function proto is not found, we conservatively assume throwing.
+    return true;
+  }
+  return !isNoexceptExceptionSpec(Proto->getExceptionSpecType()) ||
+         Proto->canThrow() != CT_Cannot;
+}
+
+static bool ResumeStmtCanThrow(const Stmt *S) {
+  if (const auto *CE = dyn_cast<CallExpr>(S)) {
+    const auto *Callee = CE->getDirectCallee();
+    if (!Callee)
+      // We don't have direct callee. Conservatively assume throwing.
+      return true;
+
+    if (FunctionCanThrow(Callee))
+      return true;
----------------
ChuanqiXu9 wrote:

```suggestion
    if (!FunctionCanThrow(Callee))
      return false;
```

nit: This reads better. In case we know the called function is nothrow, we don't need to check it further recursively especially await_resume doesn't have arguments except `this`.

https://github.com/llvm/llvm-project/pull/73160