Fix bug with module entries disambiguation and postponed fixities

This updates the disambiguation algorithm for module entries to support postponed fixity pragmas (#270).

src/parser/signature_disambiguation.ml

@@ -638,7 +638,7 @@ struct
     | Synprs.Signature.Declaration.Raw_module
         { location; identifier; entries } ->
         add_module state ~location identifier (fun state ->
-            let entries' = traverse_list state disambiguate_entry entries in
+            let entries' = disambiguate_entries state entries in
             Synext.Signature.Declaration.Module
               { location; identifier; entries = entries' })