Rollup merge of #73738 - nbdd0121:comment, r=nikomatsakis

Remove irrelevant comment

Iterator is no longer a lang item since 216e72f.

src/libcore/option.rs

@@ -142,11 +142,6 @@ use crate::{
     ops::{self, Deref, DerefMut},
 };
 
-// Note that this is not a lang item per se, but it has a hidden dependency on
-// `Iterator`, which is one. The compiler assumes that the `next` method of
-// `Iterator` is an enumeration with one type parameter and two variants,
-// which basically means it must be `Option`.
-
 /// The `Option` type. See [the module level documentation](index.html) for more.
 #[derive(Copy, PartialEq, PartialOrd, Eq, Ord, Debug, Hash)]
 #[rustc_diagnostic_item = "option_type"]