[compiler-rt] [compiler-rt] Add infrastructure for testing cpuid builtins (PR #101927)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

> It's unlike to happen. I imagine the HW spec might be updated after it's disclosed and compiler may fail to catch it.

Makes sense. Either way, seems like something that would be hard to detect even with decent testing?

> There was a bot run with SDE, but seems removed from llvm-zorg now.

Yeah, this doesn't seem too uncommon for some of the bots with specific configurations, hence my concern about limiting the tests by requiring something like SDE.

Are we able to move forward with this given testing a specific processor's CPU values and asserting microarch/features based on manufacturer documentation should alleviate concerns regarding tests being incorrectly based on the implementation?

https://github.com/llvm/llvm-project/pull/101927