This is to allow future changes to do cross-process MessagePorts in an
implementation-agnostic way. Add some tests for this behavior.
Delivering messages that were posted to a MessagePort just before it was
transferred is not yet implemented still.
Use a LocalSocket to represent the connection between two message ports.
The concept of the port message queue is still missing, however. When
that concept is implemented, the "steps" in step 7 of the message port
transfer steps will need to send the serialized data over the connected
socketpair and run in the event loop of the process that holds onto the
other side of the message port. Doing this should allow centralizing the
behavior of postMessage for Window, MessagePorts and Workers.
Also trap the invalid object index inserted for transferred values in
deserialization. In the future we should avoid inserting that
placeholder value in the data stream at all.
This implementation only works for cloning Numbers, and does not try to
do all the spec steps for structured serialize and deserialize.
Co-Authored-By: Andrew Kaster <akaster@serenityos.org>
