[llvm] [Exegesis] Add the ability to dry-run the measurement phase (PR #121991)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

> It is useful when we want to test some parts of the code between the assemble-measured-code and measure phase without actually running on native platforms.

Could you give some examples of what you're talking about here? Debugging the benchmark runners?

https://github.com/llvm/llvm-project/pull/121991