patch 8.2.2784: Vim9: cannot use \=expr in :substitute
Problem: Vim9: cannot use \=expr in :substitute.
Solution: Compile the expression into instructions and execute them when
invoked.
diff --git a/src/proto/ex_cmds.pro b/src/proto/ex_cmds.pro
index 9036dd2..1711af4 100644
--- a/src/proto/ex_cmds.pro
+++ b/src/proto/ex_cmds.pro
@@ -27,6 +27,7 @@
void ex_z(exarg_T *eap);
int check_restricted(void);
int check_secure(void);
+char_u *skip_substitute(char_u *start, int delimiter);
void ex_substitute(exarg_T *eap);
int do_sub_msg(int count_only);
void ex_global(exarg_T *eap);