8320582: Zero: Misplaced CX8 enablement flag

Reviewed-by: dholmes

src/hotspot/cpu/zero/vm_version_zero.cpp

@@ -137,6 +137,12 @@ void VM_Version::initialize() {
 #ifdef ASSERT
   UNSUPPORTED_OPTION(CountCompiledCalls);
 #endif
+
+  // Supports 8-byte cmpxchg with compiler built-ins.
+  // These built-ins are supposed to be implemented on
+  // all platforms (even if not natively), so we claim
+  // the support unconditionally.
+  _supports_cx8 = true;
 }
 
 void VM_Version::initialize_cpu_information(void) {
@@ -145,12 +151,6 @@ void VM_Version::initialize_cpu_information(void) {
     return;
   }
 
-  // Supports 8-byte cmpxchg with compiler built-ins.
-  // These built-ins are supposed to be implemented on
-  // all platforms (even if not natively), so we claim
-  // the support unconditionally.
-  _supports_cx8 = true;
-
   _no_of_cores  = os::processor_count();
   _no_of_threads = _no_of_cores;
   _no_of_sockets = _no_of_cores;