if you have `PeripheralRef<'a, AnyPIn>` for pin A, and `AnyPin` (owned) for pin B, you can `mem::swap` them.
so, getting access forever to pin A, just by "sacrificing" pin B
this defeats the point of PeripheralRef, which is if you got a `PeripheralRef<'a, T>` then you're only allowed to use the peripheral for `'a`.
Also some drivers rely on the fact only one instance of a singleton exists for soundness, so this is a soundness fix for those.
see e.g. STM32H503 RM section 15.4.4...
1. Write 1 into GPDMA_CxCR.SUSP
2. Poll GPDMA_CxSR.SUSPF until it is 1
3. Write 1 into GPDMA_CxCR.RESET (occurs upon next init, in new_inner())
- Move typelevel interrupts to a special-purpose mod: `embassy_xx::interrupt::typelevel`.
- Reexport the PAC interrupt enum in `embassy_xx::interrupt`.
This has a few advantages:
- The `embassy_xx::interrupt` module is now more "standard".
- It works with `cortex-m` functions for manipulating interrupts, for example.
- It works with RTIC.
- the interrupt enum allows holding value that can be "any interrupt at runtime", this can't be done with typelevel irqs.
- When "const-generics on enums" is stable, we can remove the typelevel interrupts without disruptive changes to `embassy_xx::interrupt`.
- Move Interrupt and InterruptExecutor from `embassy` to `embassy-cortex-m`.
- Move Unborrow from `embassy` to `embassy-hal-common` (nothing in `embassy` requires it anymore)
- Move PeripheralMutex from `embassy-hal-common` to `embassy-cortex-m`.
