disable deprecation checks for "is" identifiers (#2976)

src/context/display/deprecationCheck.ml

@@ -124,5 +124,6 @@ let run_on_field ?(force=false) com cf = if_enabled ~force com (fun() -> run_on_
 let run ?(force=false) com = if_enabled ~force com (fun() -> run com)
 
 let check_is com name meta p =
-	if name = "is" && not (Meta.has Meta.Deprecated meta) then
-		warn_deprecation com "Using \"is\" as an identifier is deprecated" p
+	()
+	(* if name = "is" && not (Meta.has Meta.Deprecated meta) then
+		warn_deprecation com "Using \"is\" as an identifier is deprecated" p *)