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

https://github.com/tranzystorek-io/void-packages llvm15
https://github.com/void-linux/void-packages/pull/40821

[WIP] LLVM 15
[ci skip]

TODO:

- [ ] Adjust patches marked as `.patch.skip`
- [x] Make libomp a shlib (change so file name and install a symlink)
- [ ] Avoid creating triplet dirs under /usr/

TODO LLVM rdeps:

- [ ] clazy
- [ ] beignet
- [ ] ispc (1.18.1 supports LLVM `<= 14`)
- [ ] ldc (1.30.0 supports LLVM `<= 14`)
- [ ] ghdl (2.0.0 supports LLVM `<=14`)
- [ ] qt, qtcreator
- [ ] bpftrace (https://github.com/void-linux/void-packages/pull/39002)

A patch file from https://github.com/void-linux/void-packages/pull/40821.patch is attached