patch 8.2.4804: expression in heredoc doesn't work for compiled function

Problem:    Expression in heredoc doesn't work for compiled function.
Solution:   Implement compiling the heredoc expressions. (Yegappan Lakshmanan,
            closes #10232)
diff --git a/src/ex_getln.c b/src/ex_getln.c
index c351cf2..a97024b 100644
--- a/src/ex_getln.c
+++ b/src/ex_getln.c
@@ -4605,7 +4605,7 @@
 	return NULL;
     cmd += 2;
 
-    l = heredoc_get(eap, cmd, TRUE);
+    l = heredoc_get(eap, cmd, TRUE, FALSE);
     if (l == NULL)
 	return NULL;