Test: enable JS string

Author: vouillon

dune

@@ -4,7 +4,10 @@
    (:standard -w +a-4-40-41-42-44-48-58-66-70))
   (binaries
    (tools/node_wrapper.exe as node)
-   (tools/node_wrapper.exe as node.exe)))
+   (tools/node_wrapper.exe as node.exe))
+  (wasm_of_ocaml
+   (flags
+    (:standard --enable use-js-string))))
  (with-effects
   (js_of_ocaml
    (compilation_mode separate)