patch 8.2.2553: Vim9: Cannot put "|" after "{"

Problem:    Vim9: Cannot put "|" after "{".
Solution:   Add the EX_TRLBAR flag. (issue #7904)
diff --git a/src/ex_eval.c b/src/ex_eval.c
index ad9de26..f6f766a 100644
--- a/src/ex_eval.c
+++ b/src/ex_eval.c
@@ -912,7 +912,7 @@
 enter_block(cstack_T *cstack)
 {
     ++cstack->cs_idx;
-    if (in_vim9script())
+    if (in_vim9script() && current_sctx.sc_sid > 0)
     {
 	scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);