[llvm] ThinLTOBitcodeWriter: Emit __cfi_check to full LTO part of bitcode file. (PR #154833)

[Eli Friedman via llvm-commits]

https://github.com/efriedma-quic approved this pull request.

As discussed in #98673, I think we should come up with a better way of specifying appropriate target features for compiler/linker-generated functions, as opposed to making every translation unit define a function named __cfi_check with the right target features attached, but fixing the bug in the existing approach seems fine for now.

I'm not an expert on ThinLTO linking, but the code looks right, and the fix seems to work for my testcases as far as I can tell.

LGTM

https://github.com/llvm/llvm-project/pull/154833