Added vita target support

[nikarh]

This fixes the compilation for armv7-sony-vita-newlibeabihf target.

• The target has no process API
• libc is bumped for Add missing PS Vita definitions, fix some unused ones rust-lang/libc#3284 and Added socketpair and pipe2 for Vita target rust-lang/libc#3366
• socket2 bumped for Add support for vita rust-lang/socket2#465

Other requirements for polling and networking to work on the target (merged but not released yet):

• Added support for vita target mio#1721

As well as setting mio_unsupported_force_poll_poll until #5866 is resolved (or if the outcome of #5866 would be to hardocde specific targets, I can hardcode it in this PR)

[Darksonn]

So, will this work once both this and tokio-rs/mio#1721 are released?

Regarding mio_unsupported_force_poll_poll, it's okay that it has the same status as other similar targets. The hard-coding fix would be nice, but make a dedicated PR for it.

[nikarh]

So, will this work once both this and tokio-rs/mio#1721 are released?

Yes, right now I'm working with patch dependencies, and tokio works with these changes.

Regarding mio_unsupported_force_poll_poll, it's okay that it has the same status as other similar targets. The hard-coding fix would be nice, but make a dedicated PR for it.

Sure, that's not an issue for this particular target anyway.
Since building for vita requires a VITASDK toolchain and running a number of CLI tools on the resulting elf to make it runnable on the device, the recommended way to build for vita is using cargo-vita, and this tool itself already passes mio_unsupported_force_poll_poll to RUSTFLAGS for build

[Darksonn]

Is this a platform it is easy to run in our CI?

[nikarh]

Is this a platform it is easy to run in our CI?

It would be easy to run check and clippy (on nightly with buildstd, same as I did for socket2 and mio). Should I add it to this PR?

Running tests though would unfortunately be impossible without the actual physical device.

[Darksonn]

Okay. In that case, please add the target here:

tokio/.github/workflows/ci.yml

Lines 405 to 426 in 881b510

	cross-check:
	name: cross-check
	needs: basics
	runs-on: ubuntu-latest
	strategy:
	matrix:
	target:
	- powerpc-unknown-linux-gnu
	- powerpc64-unknown-linux-gnu
	- arm-linux-androideabi
	steps:
	- uses: actions/checkout@v3
	- name: Install Rust ${{ env.rust_stable }}
	uses: dtolnay/rust-toolchain@stable
	with:
	toolchain: ${{ env.rust_stable }}
	target: ${{ matrix.target }}
	- uses: Swatinem/rust-cache@v2
	- run: cargo check --workspace --all-features --target ${{ matrix.target }}
	env:
	RUSTFLAGS: --cfg tokio_unstable -Dwarnings

[nikarh]

Okay. In that case, please add the target here:

tokio/.github/workflows/ci.yml

Lines 405 to 426 in 881b510

	cross-check:
	name: cross-check
	needs: basics
	runs-on: ubuntu-latest
	strategy:
	matrix:
	target:
	- powerpc-unknown-linux-gnu
	- powerpc64-unknown-linux-gnu
	- arm-linux-androideabi
	steps:
	- uses: actions/checkout@v3
	- name: Install Rust ${{ env.rust_stable }}
	uses: dtolnay/rust-toolchain@stable
	with:
	toolchain: ${{ env.rust_stable }}
	target: ${{ matrix.target }}
	- uses: Swatinem/rust-cache@v2
	- run: cargo check --workspace --all-features --target ${{ matrix.target }}
	env:
	RUSTFLAGS: --cfg tokio_unstable -Dwarnings

Sure, though as I mentioned above, check would require build-std on nightly, since vita is a Tier 3 target. I can add a new step for tier 3 targets like this:

  cross-check-tier3:
    name: cross-check-tier3
    needs: basics
    runs-on: ubuntu-latest
    strategy:
      matrix:
        target:
          - armv7-sony-vita-newlibeabihf
    steps:
      - uses: actions/checkout@v3
      - name: Install Rust ${{ env.rust_nightly }}
        uses: dtolnay/rust-toolchain@stable
        with:
          toolchain: ${{ env.rust_nightly }}
          target: ${{ matrix.target }}

      - uses: Swatinem/rust-cache@v2
      - run: cargo hack check -Zbuild-std --workspace --feature-powerset --target ${{ matrix.target }}
        env:
          RUSTFLAGS: --cfg tokio_unstable -Dwarnings

Since it will fail unless mio is released and bumped, I'll ask for a mio release, and add the CI step to this PR after that happens.

[nikarh]

Bumped mio and added a CI step.

I don't particularly like how it tuned out - vita has no process support, and signal-hook-registry won't even compile. So we can't support process, signal and as a consequence full features in check. So check can't be done for --all-features, so I've used cargo hack check --each-feature because that way I can exclude features from check.

Also vita check job needs a more recent nightly than the one in the job, and bumping it fails docs step.

[Darksonn]

I updated the nightly version. Please try again.

[nikarh]

I updated the nightly version. Please try again.

Thanks! Rebased, squashed, and added job to tests-pass.needs

[Darksonn]

Thanks.