[llvm] [DWARF] Add option to add linkage_names to call_origin declaration refs (PR #89640)

[David Blaikie via llvm-commits]

dwblaikie wrote:

> The new flag shouldn't change anything upstream whether it is enabled or not because the non-SCE-tuned behaviour upstream is to always add linkage names to subprogram DIEs, AFAICT.

By "upstream" you mean "anyone not using `-gsce`"? 

And any chance you've measured the impact of not always adding linkage names to subprogram DIEs for SCE lately? Is that optimization still pulling its weight for you, or would it be possible to converge on the non-sce behavior and remove some special cases here, rather than adding a new one?

https://github.com/llvm/llvm-project/pull/89640