Vendor dependencies

Let's see how I like this workflow.

vendor/js-sys/tests/wasm/Iterator.js

@@ -0,0 +1,19 @@
+exports.get_iterable = () => ["one", "two", "three"];
+
+exports.get_not_iterable = () => new Object;
+
+exports.get_symbol_iterator_throws = () => ({
+  [Symbol.iterator]: () => { throw new Error("nope"); },
+});
+
+exports.get_symbol_iterator_not_function = () => ({
+  [Symbol.iterator]: 5,
+});
+
+exports.get_symbol_iterator_returns_not_object = () => ({
+  [Symbol.iterator]: () => 5,
+});
+
+exports.get_symbol_iterator_returns_object_without_next = () => ({
+  [Symbol.iterator]: () => new Object,
+});