This commit adds `readable` and `writable` properties to `Deno.File` and
`Deno.Conn`. This makes it very simple to use files and network sockets
with fetch or the native HTTP server.
std/http/server knows how to handle "Listener has been closed"
exceptions but not "operation canceled" errors.
Make "unix" listen sockets throw the same exception as "tcp" listen
sockets when the socket is closed and has a pending accept operation.
There is still a discrepancy when multiple accept requests are posted
but that's probably a less visible issue and something for another day.
Fixes #13033
Currently all async ops are polled lazily, which means that op
initialization code is postponed until control is yielded to the event
loop. This has some weird consequences, e.g.
```js
let listener = Deno.listen(...);
let conn_promise = listener.accept();
listener.close();
// `BadResource` is thrown. A reasonable error would be `Interrupted`.
let conn = await conn_promise;
```
JavaScript promises are expected to be eagerly evaluated. This patch
makes ops actually do that.
This PR refactors the usages of delay utility in js unit testing. The same
utiliy is defined in several places with different names. This PR replaces those
usages with the one provided in std/async/delay.ts to improve the readability
and consistency of test code.
This commit migrates all ops to use new resource table
and "AsyncRefCell".
Old implementation of resource table was completely
removed and all code referencing it was updated to use
new system.
