AMD Zen 2 "Znver2" Optimizations With LLVM Clang 10 Bring Some Improvements

With LLVM Clang 10 having added a Zen 2 scheduler model tuned for the latest AMD CPUs over the existing "znver2" tuning that had just copied the Zen 1 scheduler, here are some benchmarks looking at the LLVM Clang 9 vs. 10 compiler performance on AMD EPYC when making use of "-march=znver2" optimizations...