[llvm] Jump table annotations for Linux (PR #112606)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

https://reviews.llvm.org/D149367 did something very similar on Windows; the way it ended up working is that it emits a pseudo-instruction to record the relationship between the jump and the corresponding jump table.

(See also #101962, which is sort of related, but not really the same thing.)

https://github.com/llvm/llvm-project/pull/112606