patch 8.2.1079: Vim9: no line break allowed in a while loop

Problem:    Vim9: no line break allowed in a while loop.
Solution:   Update stored loop lines when finding line breaks.
diff --git a/src/proto/ex_docmd.pro b/src/proto/ex_docmd.pro
index 7f5c691..8f5ac10 100644
--- a/src/proto/ex_docmd.pro
+++ b/src/proto/ex_docmd.pro
@@ -4,10 +4,11 @@
 int do_cmdline(char_u *cmdline, char_u *(*fgetline)(int, void *, int, int), void *cookie, int flags);
 int getline_equal(char_u *(*fgetline)(int, void *, int, int), void *cookie, char_u *(*func)(int, void *, int, int));
 void *getline_cookie(char_u *(*fgetline)(int, void *, int, int), void *cookie);
+char_u *getline_peek(char_u *(*fgetline)(int, void *, int, int), void *cookie);
 int parse_command_modifiers(exarg_T *eap, char **errormsg, int skip_only);
 int parse_cmd_address(exarg_T *eap, char **errormsg, int silent);
 int checkforcmd(char_u **pp, char *cmd, int len);
-char_u *find_ex_command(exarg_T *eap, int *full, void *((*lookup)(char_u *, size_t, cctx_T *)), cctx_T *cctx);
+char_u *find_ex_command(exarg_T *eap, int *full, void *(*lookup)(char_u *, size_t, cctx_T *), cctx_T *cctx);
 int modifier_len(char_u *cmd);
 int cmd_exists(char_u *name);
 cmdidx_T excmd_get_cmdidx(char_u *cmd, int len);