[llvm] [llvm] Win x64 Unwind V2 1/n: Mark beginning and end of epilogs (PR #110024)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

Can you share some high level summary of what x64 unwind v2 is? I presume it is some extension to the unwind info format used currently; is there some public documentation for the additions? Are the additions backwards compatible, or can they be enabled only if the target is known to be new enough?

https://github.com/llvm/llvm-project/pull/110024