new Array(1,2,3) was returning an empty wrapper object because
js-new-call only honoured a non-undefined return when
(type-of ret) === "dict"; SX lists (representing JS arrays) were
silently discarded. Widened the check to accept "list" too.
Fixes new Array(1,2,3).length, String(new Array(1,2,3)), and any
constructor whose body returns a list. built-ins/String:
67/99 → 69/99 (canonical). conformance.sh: 148/148.