Some bugs with stack reallocation by 'luaF_close'

(Long time without testing with '-DHARDSTACKTESTS'...)
With the introduction of to-be-closed variables, calls to 'luaF_close'
can move the stack, but some call sites where keeping pointers to the
stack without correcting them.

ljumptab.h

@@ -16,7 +16,7 @@
 #define vmbreak		vmfetch(); vmdispatch(GET_OPCODE(i));
 
 
-static void *disptab[] = {
+static void *disptab[NUM_OPCODES] = {
 
 #if 0
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