patch 8.2.0098: exe stack length can be wrong without being detected

Problem:    Exe stack length can be wrong without being detected.
Solution:   Add a check when ABORT_ON_INTERNAL_ERROR is defined.
diff --git a/src/autocmd.c b/src/autocmd.c
index 983a155..13aa065 100644
--- a/src/autocmd.c
+++ b/src/autocmd.c
@@ -1827,6 +1827,7 @@
     int		did_save_redobuff = FALSE;
     save_redo_T	save_redo;
     int		save_KeyTyped = KeyTyped;
+    ESTACK_CHECK_DECLARATION
 
     /*
      * Quickly return if there are no autocommands for this event or
@@ -2021,6 +2022,7 @@
 
     // name and lnum are filled in later
     estack_push(ETYPE_AUCMD, NULL, 0);
+    ESTACK_CHECK_SETUP
 
 #ifdef FEAT_EVAL
     save_current_sctx = current_sctx;
@@ -2124,6 +2126,7 @@
     filechangeshell_busy = FALSE;
     autocmd_nested = save_autocmd_nested;
     vim_free(SOURCING_NAME);
+    ESTACK_CHECK_NOW
     estack_pop();
     vim_free(autocmd_fname);
     autocmd_fname = save_autocmd_fname;