Move to a newer toolchain

[TenSeventy7]

The current Proton Clang/LLVM 13 toolchain Mint Kernel is using no longer works properly on newer glibc versions, notably shipping versions on Fedora 37. I've been building them locally using an Ubuntu 22.04 toolbox instance, but even this isn't sustainable.

We have two options, both will need work on the source tree.

1. Upgrade the LLVM toolchain we're using. We would need to determine the new optimizations as building with them results into an unbootable kernel.

2. Move to GCC, even Cruel-GCC 11.x works fine. Our tree has a significant amount of code quality issues that needs fixing if we want to fully take advantage of this toolchain, though.