1948288615
Do not report cycle error when inferring return type for suggestion The UI test is a good example of a case where this happens. The cycle is due to needing the value of the return type `-> _` to compute the variances of items in the crate, but then needing the variances of the items in the crate to do typechecking to infer what `-> _`'s real type is. Since we're already gonna emit an error in astconv, just delay the cycle bug as an error.
For more information about how rustc works, see the rustc dev guide.