patch 9.0.1569: cannot use "this.member" in lambda in class method

Problem:    Cannot use "this.member" in lambda in class method.
Solution:   Adjust check for reserved keyword. (Hirohito Higashi,
            closes #12416, closes #12076, closes #12336)
diff --git a/src/vim9script.c b/src/vim9script.c
index 5bf2cc7..b1849db 100644
--- a/src/vim9script.c
+++ b/src/vim9script.c
@@ -838,7 +838,7 @@
     // parse type, check for reserved name
     p = skipwhite(p + 1);
     type = parse_type(&p, &si->sn_type_list, TRUE);
-    if (type == NULL || check_reserved_name(name, NULL) == FAIL)
+    if (type == NULL || check_reserved_name(name, FALSE) == FAIL)
     {
 	vim_free(name);
 	return p;
@@ -1127,17 +1127,13 @@
 };
 
     int
-check_reserved_name(char_u *name, cctx_T *cctx)
+check_reserved_name(char_u *name, int is_objm_access)
 {
     int idx;
 
     for (idx = 0; reserved[idx] != NULL; ++idx)
 	if (STRCMP(reserved[idx], name) == 0
-		// "this" can be used in an object method
-		&& !(STRCMP("this", name) == 0
-		    && cctx != NULL
-		    && cctx->ctx_ufunc != NULL
-		    && (cctx->ctx_ufunc->uf_flags & (FC_OBJECT|FC_NEW))))
+		&& !(STRCMP("this", name) == 0 && is_objm_access))
 	{
 	    semsg(_(e_cannot_use_reserved_name_str), name);
 	    return FAIL;