In #9118, TLS streams were split into a "read half" and a "write half"
using tokio::io::split() to allow concurrent Conn#read() and
Conn#write() calls without one blocking the other. However, this
introduced a bug: outgoing data gets discarded when the TLS stream is
gracefully closed, because the read half is closed too early, before all
TLS control data has been received.
Fixes: #9692
Fixes: #10049
Fixes: #10296
Fixes: denoland/deno_std#750
`InvalidDNSNameError` is thrown when a string is not a valid hostname,
e.g. it contains invalid characters, or starts with a numeric digit. It
does not involve a (failed) DNS lookup.
This removes the std folder from the tree.
Various parts of the tests are pretty tightly dependent
on std (47 direct imports and 75 indirect imports, not
counting the cli tests that use them as fixtures) so I've
added std as a submodule for now.