Reland "[llvm-exegesis] Refactor parent code to separate function (#86232)"
This reverts commit c3a41aac5f32475b9a0499e6e888e713763566dc.
This relands commit bd493756fa51e538575fc320aae50d75394f0567.
Apparently I forgot to update a couple values, so this change failed on
every builder that builds those sections (should be every Linux
platform) rather than something architecture specific like originally
thought. I swore I updated the values and ran check-llvm before merging.
Wondering If I forgot to push those changes...