[llvm] [llvm-exegesis] Switch from MCJIT to LLJIT (PR #72838)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

> This broke lit tests on Mac, see https://green.lab.llvm.org/green/job/clang-stage1-cmake-RA-incremental/38602/

Thanks for the revert. That test shouldn't be running on Darwin or Windows, so I've specified it requires Linux, which should fix the issue. I'll keep an eye on that bot and make sure everything goes through.

https://github.com/llvm/llvm-project/pull/72838