pars_info_add_*(): In debug builds (UNIV_DEBUG), check that the given name

is not already used.

pars/pars0pars.c

@@ -1963,6 +1963,8 @@ pars_info_add_literal(
 {
 	pars_bound_lit_t*	pbl;
 
+	ut_ad(!pars_info_get_bound_lit(info, name));
+
 	pbl = mem_heap_alloc(info->heap, sizeof(*pbl));
 
 	pbl->name = name;
@@ -2053,6 +2055,8 @@ pars_info_add_function(
 {
 	pars_user_func_t*	puf;
 
+	ut_ad(!pars_info_get_user_func(info, name));
+
 	puf = mem_heap_alloc(info->heap, sizeof(*puf));
 
 	puf->name = name;