[llvm] [ExecutionEngine] reinstate necessary include for building with `-DLLVM_USE_INTEL_JITEVENTS` (PR #117949)

[via llvm-commits]

h-vetinari wrote:

> Yes, moving the include behind `#if LLVM_USE_INTEL_JITEVENTS` sounds good.

It would have been a trivial update to this PR, but whatever gets this fixed. ;-)

https://github.com/llvm/llvm-project/pull/117949