use test mode to test the interpreter without jump tables

ltests.h

@@ -1,5 +1,5 @@
 /*
-** $Id: ltests.h,v 2.55 2017/12/18 13:01:49 roberto Exp roberto $
+** $Id: ltests.h,v 2.56 2018/02/27 18:47:32 roberto Exp roberto $
 ** Internal Header for Debugging of the Lua Implementation
 ** See Copyright Notice in lua.h
 */
@@ -41,6 +41,10 @@
 #endif
 
 
+/* get a chance to test code without jump tables */
+#define LUA_USE_JUMPTABLE	0
+
+
 /* memory-allocator control variables */
 typedef struct Memcontrol {
   unsigned long numblocks;