[clang] [clang-tools-extra] [llvm] [llvm-exegesis] Replace --num-repetitions with --min-instructions (PR #77153)

[Aiden Grossman via cfe-commits]

boomanaiden154 wrote:

@legrosbuffle This is ready for review when you have a chance. Thanks!

https://github.com/llvm/llvm-project/pull/77153