Optimizations for AMD Bulldozer

- Added support for XOP instructions
- Enabled Ryzen code for Bulldozer because it's faster there too

src/crypto/randomx/randomx.h

@@ -49,7 +49,7 @@ enum randomx_flags {
   RANDOMX_FLAG_FULL_MEM = 4,
   RANDOMX_FLAG_JIT = 8,
   RANDOMX_FLAG_1GB_PAGES = 16,
-  RANDOMX_FLAG_RYZEN = 64,
+  RANDOMX_FLAG_AMD = 64,
 };