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)

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4804,
 /**/
     4803,
 /**/