Revert "Uniform Arguments for simple_type"

This reverts commit f4a6ea09.

theories/typing/type.v

@@ -121,8 +121,6 @@ Record simple_type `{!typeG Σ} :=
 Existing Instance st_own_persistent.
 Instance: Params (@st_own) 2 := {}.
 
-Arguments st_own {_ _} _ / : simpl nomatch.
-
 Program Definition ty_of_st `{!typeG Σ} (st : simple_type) : type :=
   {| ty_size := 1; ty_own := st.(st_own);
      (* [st.(st_own) tid vl] needs to be outside of the fractured