[compiler-rt] [llvm] [lit] [compiler-rt] Add llvm-lit global command cache to speed up test config (PR #195888)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 approved this pull request.

LGTM. It would probably be nice if we could standardize on this within all the lit configs, although I suspect it would be less useful outside of compiler-rt and likely a lot of work.

https://github.com/llvm/llvm-project/pull/195888