Glibc-HWCAPS To Help With AMD Zen Optimizations, Other Per-CPU Performance Bits

Experimental patches under discussion for the GNU C Library (glibc) would make it easier to dynamically load optimized libraries (shared objects) on systems depending upon the CPU in use and its hardware capabilities. This glibc-hwcaps work stems from the desired work on being able to better leverage Linux performance optimizations on AMD Zen-based systems but the hardware capabilities patches themselves can help any CPU microarchitecture family in more easily shipping optimized support...