core/exec: Correctly pop loops when CONTINUE_OP is called

This fixes an issue where a Continue would not pop the actual loop itself,
which would manifest in weird execution flow.

Fixes #141

core/exec.c

@@ -2400,7 +2400,7 @@ static lai_api_error_t lai_exec_parse(int parse_mode, lai_state_t *state) {
             }
 
             // Pop all nested loops/conditions.
-            for (int i = 0; i < m; i++) {
+            for (int i = 0; i < (m + 1); i++) {
                 lai_stackitem_t *pop_item = lai_exec_peek_stack_back(state);
                 LAI_ENSURE(pop_item->kind == LAI_COND_STACKITEM
                            || pop_item->kind == LAI_LOOP_STACKITEM);