[clang] [llvm] [HLSL] Run finalize linkage pass for all targets (PR #134260)

[Eli Friedman via llvm-commits]

https://github.com/efriedma-quic commented:

I'm not sure I understand why we're changing the linkage of functions in an IR pass, instead of just setting the correct linkage in the first place.  Is there some form of linker involved?  If there is, should the linker fix the linkage?

By convention, passes which are required for correctness are part of the backend, so you can't accidentally skip running them.  (This isn't 100%, but we try when possible.)  If this needs to be target-independent, you can stick it in the target-independent TargetMachine code that computes the pass pipeline.  Adding it in clang means every other frontend needs an equivalent change.

https://github.com/llvm/llvm-project/pull/134260