patch 8.2.3946: when an internal error makes Vim exit the error is not seen

Problem:    When an internal error makes Vim exit the error is not seen.
Solution:   Add the error to the test output.
diff --git a/src/message.c b/src/message.c
index 7e98d0b..8768065 100644
--- a/src/message.c
+++ b/src/message.c
@@ -824,10 +824,13 @@
 iemsg(char *s)
 {
     if (!emsg_not_now())
+    {
 	emsg_core((char_u *)s);
 #ifdef ABORT_ON_INTERNAL_ERROR
-    abort();
+	set_vim_var_string(VV_ERRMSG, (char_u *)s, -1);
+	abort();
 #endif
+    }
 }
 
 #ifndef PROTO  // manual proto with __attribute__