There is an updated pull request by Calandracas606 against master on the void-packages repository

https://github.com/Calandracas606/void-packages llvm17-fixup
https://github.com/void-linux/void-packages/pull/48625

llvm17: fixup and refactor
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#### Testing the changes
- I tested the changes in this PR: **NO**

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#### Local build testing
- I built this PR locally for my native architecture, x86_64-musl

Fixes an issue where clang17 fails to compile anything due to missing headers (stddef.h)

In the meantime, clang17-devel needs to be installed to use clang17

[ci skip]

closes #48616

A patch file from https://github.com/void-linux/void-packages/pull/48625.patch is attached