sys-devel/llvm-16.0.4 fails to build with -fipa-pta

[SigHunter]

just a heads up, sys-devel/llvm-16.0.4, which came to ::gentoo ~amd64 about a week ago fails to build with -fipa-pta
had to make an exception for it via sys-devel/llvm *FLAGS-="${IPAPTA}" and then it built fine

also related on gentoo bug tracker, not by me https://bugs.gentoo.org/906751

the last few pages of the build log

[elsandosgrande]

Funnily enough, for me, this didn't cause LLVM to fail to build, but instead caused Clang to, depending on which flags I built it with, either fail to build or, if it did build, to fail to compile anything because LLVM crashed. I've been fighting with Clang for most of May and only saw this once I gave up last week and went to watch things on my laptop after only being able to use my phone for several weeks 🥲

Surprisingly enough, Mesa drivers have no issues with running on top of LLVM 16.0.5 that's been built with -fipa-pta on my laptop.

[paralin]

I had llvm failing to build and after merging #886 it builds correctly.