[llvm] Reland: "[Exegesis] Add the ability to dry-run the measurement phase (#121991)" (PR #122775)

[Min-Yih Hsu via llvm-commits]

mshockwave wrote:

> We are seeing MAC test failures as well in Fuchsia toolchain builders:
> 
> https://luci-milo.appspot.com/ui/p/fuchsia/builders/toolchain.ci/clang-host-mac-x64/b8725747943317383073/overview

It's hot fixed by https://github.com/llvm/llvm-project/commit/63d3bd6d0caf8185aba49540fe2f67512fdf3a98
I simply moved this test into test/tools/llvm-exegesis/X86 and gated with `exegesis-can-execute-x86_64`.

https://github.com/llvm/llvm-project/pull/122775