gentype: support Jsx.element in addition to React.element

The type Jsx.element can show user-side in ppx V4 (at least), and affects gentype too.
It special-cases `React.element`, and needs to then special-case `Jsx.element` too.

Fixes #6807

Author: cristianoc

jscomp/gentype/TranslateTypeExprFromTypes.ml

@@ -216,7 +216,8 @@ let translate_constr ~config ~params_translation ~(path : Path.t) ~type_env =
     {dependencies = []; type_ = EmitType.type_react_event_mouse_t}
   | ( ( ["React"; "element"]
       | ["ReactV3"; "React"; "element"]
-      | ["ReasonReact"; "reactElement"] ),
+      | ["ReasonReact"; "reactElement"]
+      | [("Pervasives" | "PervasivesU"); "Jsx"; "element"] ),
       [] ) ->
     {dependencies = []; type_ = EmitType.type_react_element}
   | (["FB"; "option"] | ["option"]), [param_translation] ->