patch 8.2.1071: Vim9: no line break allowed inside a lambda

Problem:    Vim9: no line break allowed inside a lambda.
Solution:   Handle line break inside a lambda in Vim9 script.
diff --git a/src/ex_eval.c b/src/ex_eval.c
index 8b8a256..6f6b8c2 100644
--- a/src/ex_eval.c
+++ b/src/ex_eval.c
@@ -897,6 +897,7 @@
     typval_T	tv;
     evalarg_T	evalarg;
 
+    CLEAR_FIELD(evalarg);
     evalarg.eval_flags = eap->skip ? 0 : EVAL_EVALUATE;
     evalarg.eval_cookie = eap->getline == getsourceline ? eap->cookie : NULL;