Fix a comment

Author: scottmcm

library/core/src/mem/mod.rs

@@ -729,7 +729,7 @@ pub const fn swap<T>(x: &mut T, y: &mut T) {
     cfg_if! {
         // NOTE(eddyb) SPIR-V's Logical addressing model doesn't allow for arbitrary
         // reinterpretation of values as (chunkable) byte arrays, and the loop in the
-        // block optimization in `typed_swap_many` is hard to rewrite back
+        // block optimization in `ptr::swap_nonoverlapping` is hard to rewrite back
         // into the (unoptimized) direct swapping implementation, so we disable it.
         if #[cfg(any(target_arch = "spirv"))] {
             swap_simple(x, y)