crypto: account for disabled SharedArrayBuffer

PR-URL: #50034
Reviewed-By: Filip Skokan <panva.ip@gmail.com>
Reviewed-By: Matthew Aitken <maitken033380023@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

lib/internal/crypto/webidl.js

@@ -184,7 +184,10 @@ function isNonSharedArrayBuffer(V) {
 }
 
 function isSharedArrayBuffer(V) {
-  return ObjectPrototypeIsPrototypeOf(SharedArrayBuffer.prototype, V);
+  // SharedArrayBuffers can be disabled with --no-harmony-sharedarraybuffer.
+  if (SharedArrayBuffer !== undefined)
+    return ObjectPrototypeIsPrototypeOf(SharedArrayBuffer.prototype, V);
+  return false;
 }
 
 converters.Uint8Array = (V, opts = kEmptyObject) => {