remove Canonical::unchecked_rebind, it's unused

Author: lcnr

compiler/rustc_type_ir/src/canonical.rs

@@ -57,16 +57,6 @@ impl<I: Interner, V> Canonical<I, V> {
         let Canonical { defining_opaque_types, max_universe, variables, value } = self;
         Canonical { defining_opaque_types, max_universe, variables, value: map_op(value) }
     }
-
-    /// Allows you to map the `value` of a canonical while keeping the same set of
-    /// bound variables.
-    ///
-    /// **WARNING:** This function is very easy to mis-use, hence the name! See
-    /// the comment of [Canonical::unchecked_map] for more details.
-    pub fn unchecked_rebind<W>(self, value: W) -> Canonical<I, W> {
-        let Canonical { defining_opaque_types, max_universe, variables, value: _ } = self;
-        Canonical { defining_opaque_types, max_universe, variables, value }
-    }
 }
 
 impl<I: Interner, V: fmt::Display> fmt::Display for Canonical<I, V> {