tests: restore disabled tests and benches for BiLock

[LizardWizzard]

Hi! I was curious about BiLock internals (came there from its usage in split) so the easiest way to play with something is to poke into corresponding tests. Found out that tests and benchmarks for BiLock are disabled so I went ahead with reviving them to be up to date with current landscape.

Thank you your great work on the library!

[LizardWizzard]

Miri complains:

error: unsupported operation: integer-to-pointer casts and `ptr::from_exposed_addr` are not supported with `-Zmiri-strict-provenance`
   --> /home/runner/work/futures-rs/futures-rs/futures-util/src/lock/bilock.rs:178:31
    |
178 |                 Box::from_raw(n as *mut Waker).wake();
    |                               ^^^^^^^^^^^^^^^ integer-to-pointer casts and `ptr::from_exposed_addr` are not supported with `-Zmiri-strict-provenance`
    |
    = help: use Strict Provenance APIs (https://doc.rust-lang.org/nightly/std/ptr/index.html#strict-provenance, https://crates.io/crates/sptr) instead

Will it be desirable to go ahead with https://crates.io/crates/sptr as suggested in the error message?

[LizardWizzard]

Thanks @taiki-e! I've rebased it on top of current master.

CI / cargo +beta build (pull_request) failed once with:

warning: spurious network error (10 tries remaining): [35] SSL connect error (error:1408F119:SSL routines:ssl3_get_record:decryption failed or bad record mac)
...
error: failed to verify the checksum of `byteorder v1.4.3`

[taiki-e]

Thanks!

[LizardWizzard]

Thanks for review! Fixed the comments, please take another look