When simplifying canonical aliases, don't strip aliases

The logic behind stripping the Alias was that in the vast majority
of cases, the canonical path points to a module that's the alias of
the actual hidden module. This isn't always a valid assumption -
for example in `base.caml`, which creates canonical aliases to stdlib.

Author: jonludlam

src/xref2/tools.ml

@@ -941,16 +941,7 @@ and reresolve_module : Env.t -> Cpath.Resolved.module_ -> Cpath.Resolved.module_
       match
         resolve_module ~mark_substituted:true ~add_canonical:false env p2
       with
-      | Ok (`Alias (_, p2'), _) ->
-          `Canonical
-            ( reresolve_module env p,
-              `Resolved (simplify_resolved_module_path env p2') )
-      | Ok (p2', _) ->
-          (* See, e.g. Base.Sexp for an example of where the canonical path might not be
-             a simple alias *)
-          `Canonical
-            ( reresolve_module env p,
-              `Resolved (simplify_resolved_module_path env p2') )
+      | Ok (p2', _) -> `Canonical(reresolve_module env p, `Resolved (simplify_resolved_module_path env p2') )
       | Error _ -> `Canonical (reresolve_module env p, p2)
       | exception _ -> `Canonical (reresolve_module env p, p2))
   | `OpaqueModule m -> `OpaqueModule (reresolve_module env m)