Selective fix for js_pass_flatten_and_mark_dead

Author: cknitt

compiler/core/js_pass_flatten_and_mark_dead.ml

@@ -245,6 +245,10 @@ let subst_map (substitution : J.expression Hash_ident.t) =
                turn a runtime crash into compile time crash : )
             *)
             match Ext_list.nth_opt ls (Int32.to_int i) with
+            (* 7432: prevent optimization in JSX preserve mode *)
+            | Some {expression_desc = J.Var (Id {name = "make"})}
+              when !Js_config.jsx_preserve ->
+              super.expression self x
             | Some
                 ({expression_desc = J.Var _ | Number _ | Str _ | Undefined _} as
                  x) ->