BE: fix currently unused enum variant warning

Summary:
We recently (D59634903) switched to reporting the module:function range for various diagnostics.

This means the `UseRange::WithArgs` constructor is currently unused.

We will need it in future, so just silence the warning for now.

Reviewed By: jcpetruzza

Differential Revision: D59684583

fbshipit-source-id: 8efad049da3902cc9b4d20043c0fca61267dba5e

crates/ide/src/codemod_helpers.rs

@@ -479,6 +479,7 @@ pub type MakeDiag<'a, T> = &'a dyn Fn(MakeDiagCtx<T>) -> Option<Diagnostic>;
 
 #[derive(Eq, PartialEq, Copy, Clone, Debug)]
 pub enum UseRange {
+    #[allow(dead_code)]
     WithArgs,
     NameOnly,
 }