Benchmarking LLVM/Clang's New AMD Zen Scheduler Model

Znver1 tuning has very little benefit to libjpeg-turbo's performance as measured by tjbench.

The PostgreSQL performance varies from being the same as Clang 4.0 to being slower with the newest compiler code.

Redis sees some slightly increases in performance with the newest Clang compiler.

Apache also sees a very slight increase out of this SVN code that will be released as stable next month.

Overall these results are interesting and there are several cases where LLVM Clang SVN (5.0) is performing better than Clang 4.0 but there is also some cases of regressions, including when making use of znver1 tuning. Stay tuned for similar GCC 8.0 SVN benchmarks.