patch 9.1.1852: vim9class: memory leak in parse_member()

Problem:  vim9class: fix memory leak in parse_member()
Solution: Free evalarg before returning (Lidong Yan)

In parse_member(), skip_expr_concatenate() allocates memory in evalarg.
However parse_member() forgets to free evalarg at early return-fail
point. Add clear_evalarg() at early return-fail point.

closes: #18533

Signed-off-by: Lidong Yan <502024330056@smail.nju.edu.cn>
Signed-off-by: Christian Brabandt <cb@256bit.org>

Author: brandb97

src/version.c

@@ -729,6 +729,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1852,
 /**/
     1851,
 /**/

src/vim9class.c

@@ -135,6 +135,7 @@ parse_member(
 	if (*init_arg != NUL && !vim9_comment_start(init_arg))
 	{
 	    semsg(_(e_trailing_characters_str), init_arg);
+	    clear_evalarg(&evalarg, NULL);
 	    return FAIL;
 	}