ssa: cvtNamed check typeargs

cl/_testgo/tpnamed/in.go

@@ -0,0 +1,26 @@
+package main
+
+type Void = [0]byte
+type Future[T any] func() T
+
+type IO[T any] func() Future[T]
+
+func WriteFile(fileName string) IO[error] {
+	return func() Future[error] {
+		return func() error {
+			return nil
+		}
+	}
+}
+
+func RunIO[T any](call IO[T]) T {
+	return call()()
+}
+
+func main() {
+	RunIO[Void](func() Future[Void] {
+		return func() (ret Void) {
+			return
+		}
+	})
+}