Add vzeroupper for processors with AVX

To avoid false dependencies on upper 128 bits of YMM registers.

src/crypto/randomx/jit_compiler_x86.hpp

@@ -73,6 +73,7 @@ namespace randomx {
 		uint32_t vm_flags;
 
 		static bool BranchesWithin32B;
+		bool hasAVX;
 
 		static void applyTweaks();
 		void generateProgramPrologue(Program&, ProgramConfiguration&);