AMD Zen 2 "Znver2" Compiler Optimizations Back-Ported For GCC 9.2 Compiler

Last week I wrote about the GCC 10 compiler picking up a new scheduler model and cost tables for AMD Zen 2 CPUs to build off the initial "znver2" microarchitecture target from last year. Fortunately, those Znver2-specific improvements have now been back-ported to the GCC 9 compiler branch so it will see user systems with not as long of a wait until GCC 10 stable...