support for typedefs and typeconsts

Summary:
This diff adds support for typedefs and typeconsts to `hh --find-my-tests`.

For a typedef, `type Foo = ...`:
- If `Foo` is directly mentioned in a test in any way, we select that test.
- If `Foo` appears in the definition of another typedef `Bar` or typeconst `Bar::TBar`, we add `Bar`/`Bar::TBar` to our search.
- If `Foo::class` or `nameof Foo` appears in the body of some method `m`, we add `m` to our search.

For a tyepconst, `Foo::TFoo:
- If `Foo::TFoo` is directly mentioned in a test in any way, we select that test.
- If `Foo::TFoo` appears in the definition of another typedef `Bar` or typeconst `Bar::TBar`, we add `Bar`/`Bar::TBar` to our search.
- If `type_structure(Foo::class, 'TFoo')` appears in some method `m`, we add `m` to our search.

Implementation notes:
- I've factored out some code shared by `get_method_references` and `get_class_references` into `get_references_standard`, which causes some noise in this diff.
- The code for getting all references to a type constant `Foo::TFoo` (`get_typeconst_references`) is more complicated that code for other constructs:
  + For most heuristics, we need to find all references to `Foo::TFoo` directly.
  + For handling `type_structure(Foo::class, 'TFoo')`, we need to find all references to class `Foo`, and then inspect its use sites to look if it's one of the `type_structure` calls we are interested in.

Reviewed By: madgen

Differential Revision: D88656532

fbshipit-source-id: 6ce3bfebbe26f3adfc787e0cc26d78f27e133699

Author: frank-emrich

hphp/hack/src/client/clientCheck.ml

@@ -1043,10 +1043,12 @@ let main_internal
             | Some "Method"
             | None ->
               Method { class_name; member_name }
+            | Some "Typeconst" -> Typeconst { class_name; member_name }
             | Some _ -> raise Exit_status.(Exit_with Input_error))
           ~name_only_action:(fun name ->
             match kind with
             | Some "Class" -> Class { class_name = name }
+            | Some "Typedef" -> Typedef { name }
             | Some _
             | None ->
               raise Exit_status.(Exit_with Input_error))

hphp/hack/src/client_and_server/serverCommandTypes.ml

@@ -159,7 +159,9 @@ module Find_my_tests = struct
 
   type action =
     | Class of { class_name: string }
+    | Typedef of { name: string }
     | Method of member
+    | Typeconst of member
   [@@deriving show]
 
   type result_entry = {