patch 8.2.1075: Vim9: no line break allowed in :echo expression

Problem:    Vim9: no line break allowed in :echo expression.
Solution:   Skip linebreak.
diff --git a/src/eval.c b/src/eval.c
index ca98d2e..7360239 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -5190,6 +5190,7 @@
 
     CLEAR_FIELD(evalarg);
     evalarg.eval_flags = eap->skip ? 0 : EVAL_EVALUATE;
+    evalarg.eval_cookie = eap->getline == getsourceline ? eap->cookie : NULL;
 
     if (eap->skip)
 	++emsg_skip;