Use `critical_section` for `Peripherals::take`.

[reitermarkus]

• cortex_m https://github.com/rust-embedded/cortex-m/pull/447
• msp430 https://github.com/rust-embedded/msp430/issues/13
• riscv https://github.com/rust-embedded/riscv/pull/110
• xtensa_lx https://github.com/esp-rs/xtensa-lx/issues/20, https://github.com/esp-rs/esp-hal/pull/151
• mips_mcu https://github.com/kiffie/pic32-rs/issues/5

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @therealprof (or someone else) soon.

Please see the contribution instructions for more information.

[adamgreig]

I'm a bit concerned about what this means for platforms that don't have critical-section support yet. I know msp430 is working on it but having some codegen size issues, and I don't know anything about mips_mcu. It might be worth waiting a little longer for those architectures to get support before releasing svd2rust that uses it?

Having it as an optional dependency/feature seems useful though and does mean those platforms don't need immediate critical-section support, even end-users could add simple interrupt-based implementations to use take() if needed.

[reitermarkus]

It might be worth waiting a little longer

I don't think it's worth waiting. Other architectures will have to implement these only once they upgrade svd2rust anyways. I have opened issues for the affected architectures to give them a heads up though.

[adamgreig]

Oh, thanks, I didn't see the edit to the first comment. SGTM to me then.

[bors[bot]]

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