VirtualMachine: Fix repeat loop crash

* the register must be freed after it is read (not before)

Author: adazem009

src/engine/virtualmachine.cpp

@@ -152,8 +152,8 @@ unsigned int *VirtualMachine::run(unsigned int *pos, RunningScript *script)
         run(pos, script);
 
 do_repeat_loop:
-    FREE_REGS(1);
     loopCount = READ_LAST_REG()->toLong();
+    FREE_REGS(1);
     if (loopCount <= 0) {
         loopEnd = pos;
         while (*loopEnd != OP_LOOP_END && *loopEnd != OP_HALT)