Move to Rust SVD library for STM32

[kenbell]

The discussion here tinygo-org/cmsis-svd#7 concluded we could look at moving TinyGo to use the rust SVD library (https://github.com/stm32-rs/stm32-rs) for STM32 devices.

A first pass implementation is implemented in this PR: #1550

[aykevl]

@kenbell thank you for getting things started, but as I indicated, I was already working on this feature. I've made somewhat similar changes to gen-device-svd, but merging all enum fields (with the same value) to a single field instead of duplicating them with added suffixes. I'm also still working on fixing stm32 support to be able to use this new repository: some changes are needed in the runtime and machine packages.

This change requires some environment changes to generate the device/stm32 source:

• python3 to be installed
• svdtools to be installed (pip3 install --upgrade --user svdtools)

I'm working on creating a repository with just the patched SVD files, avoiding these build dependencies (which I would really like to avoid, they will complicate things).

[kenbell]

That's cool - this change is letting me keep trucking and raise PRs against stm32-rs for now. Avoiding python3 and svdtools dependency does sound like a better approach.

[aykevl]

I have made a PR here: #1557

It does a lot more, it also removes the handcrafted bitifield files from src/device/stm32 and in that process fixes some bugs (hopefully). But I've tried to avoid any other changes.

[aykevl]

Also, I've seen you fixed the timer interrupt issue upstream. Thank you!

[deadprogram]

This has been released with v0.17.0 so now closing. Thanks!