Update comment

Author: cknitt

compiler/ml/translcore.ml

@@ -419,8 +419,8 @@ let is_null_undefined_constant (exp : Typedtree.expression) =
   | _ -> false
 
 let warn_on_polymorphic_comparison loc prim_name args = function
-  (* Preserve the backend's old exemption for == / != against nullish constants,
-     which compile to dedicated null/undefined checks rather than object compare. *)
+  (* Skip warning 102 for `==` / `!=` when one side is a nullish constant:
+     those cases lower to dedicated null/undefined checks, not object comparison. *)
   | Pobjcomp (Ceq | Cneq)
     when prim_name = "%equal_null"
          || prim_name = "%equal_undefined"