HTML: ensure serializing SharedArrayBuffer throws without COOP+COEP

For whatwg/html#4734.

Author: annevk

html/infrastructure/safe-passing-of-structured-data/shared-array-buffers/no-coop-coep.https.any.js

@@ -0,0 +1,18 @@
+test(() => {
+  const sab = new SharedArrayBuffer();
+  const channel = new MessageChannel();
+  assert_throws("DataCloneError", () => channel.port1.postMessage(sab));
+}, "SharedArrayBuffer over MessageChannel without COOP+COEP");
+
+test(() => {
+  const sab = new SharedArrayBuffer();
+  const channel = new BroadcastChannel("Is mir egal");
+  assert_throws("DataCloneError", () => channel.postMessage(sab));
+}, "SharedArrayBuffer over BroadcastChannel without COOP+COEP");
+
+if (self.GLOBAL.isWindow()) {
+  test(() => {
+    const sab = new SharedArrayBuffer();
+    assert_throws("DataCloneError", () => self.postMessage(sab));
+  }, "SharedArrayBuffer over postMessage() without COOP+COEP");
+}