[llvm] [RISCV] Add TuneJumpIsExpensive (PR #191374)

[Craig Topper via llvm-commits]

topperc wrote:

What is the advantage of a tuning flag given that we already have `-mllvm -jump-is-expensive`?

Could we put it in `RISCVTuneInfo` if we want to enable it on a specific CPU?

https://github.com/llvm/llvm-project/pull/191374