patch 8.2.1067: expression "!expr->func()" does not work

Problem:    Expression "!expr->func()" does not work.
Solution:   Apply plus and minus earlier. (closes #6348)
diff --git a/src/proto/eval.pro b/src/proto/eval.pro
index 6ae770c..16ba95b 100644
--- a/src/proto/eval.pro
+++ b/src/proto/eval.pro
@@ -53,7 +53,7 @@
 char_u *find_name_end(char_u *arg, char_u **expr_start, char_u **expr_end, int flags);
 int eval_isnamec(int c);
 int eval_isnamec1(int c);
-int handle_subscript(char_u **arg, typval_T *rettv, int flags, int verbose, char_u *start_leader, char_u **end_leaderp);
+int handle_subscript(char_u **arg, typval_T *rettv, int flags, int verbose);
 int item_copy(typval_T *from, typval_T *to, int deep, int copyID);
 void echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr);
 void ex_echo(exarg_T *eap);