Add a cycle_detection parameter to the variance_map

Summary:
We need `cycle_detection` so that we can parse annotations. For example, to get the base classes, we find them in the class summary and use `parse_annotation` to convert them to a type, so we can extract the type parameters and their variance.

I don't think we should expose `cycle_detection` to other files, which is why the mli file of attributeResolution is unmodified.

I initialize `cycle_detection` to the empty cycle delection when invoking the `variance_map` method.

Wondering if this is the right way of doing it, hence RFC.

Reviewed By: stroxler

Differential Revision: D63658565

fbshipit-source-id: ad2e769977a73f8185662a5f2e2b1505bef49e5c

source/analysis/attributeResolution.ml

@@ -2877,7 +2877,8 @@ class base ~queries:(Queries.{ controls; _ } as queries) =
       | _ -> None
 
     (* We will expose this interface as the variance map *)
-    method variance_map ~class_name ~parameters =
+    method variance_map ~cycle_detections ~class_name ~parameters =
+      let _cycle_detections = cycle_detections in
       (* Creates a function from generic type parameters for a given class to post variance
          inference *)
       let infer_variance_for_one_param ~generic_type_param =
@@ -3026,7 +3027,7 @@ class base ~queries:(Queries.{ controls; _ } as queries) =
         get_typed_dictionary = self#get_typed_dictionary ~cycle_detections;
         get_named_tuple_fields;
         metaclass;
-        variance_map = self#variance_map;
+        variance_map = self#variance_map ~cycle_detections;
       }
 
     (* Given an expression, produce a Type.t where literal type information - that is,
@@ -4197,10 +4198,8 @@ module ReadOnly = struct
         ~dependency:None
         ~class_metadata_environment:(class_metadata_environment read_only)
     in
-
     let implementation = new base ~queries in
-
-    implementation#variance_map
+    implementation#variance_map ~cycle_detections:empty_cycle_detections
 
 
   let instantiate_attribute =