Apply suggestions from code review

Co-authored-by: Ralf Jung <[email protected]>

Author: saethlin

compiler/rustc_const_eval/src/interpret/terminator.rs

@@ -297,7 +297,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         // Check if this is `Option` wrapping some type or if this is `Result` wrapping a 1-ZST and
         // another type.
         let ty::Adt(def, args) = layout.ty.kind() else {
-            // Not an `Option` or Result.
+            // Not an ADT, so definitely no NPO.
             return Ok(layout);
         };
         let inner = if self.tcx.is_diagnostic_item(sym::Option, def.did()) {
@@ -312,10 +312,10 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             } else if rhs.is_1zst() {
                 lhs
             } else {
-                return Ok(layout);
+                return Ok(layout); // no NPO
             }
         } else {
-            return Ok(layout);
+            return Ok(layout); // no NPO
         };
 
         // Check if the inner type is one of the NPO-guaranteed ones.