patch 8.1.0743: giving error messages is not flexible
Problem: Giving error messages is not flexible.
Solution: Add semsg(). Change argument from "char_u *" to "char *", also
for msg() and get rid of most MSG macros. (Ozaki Kiichi, closes
#3302) Also make emsg() accept a "char *" argument. Get rid of
an enormous number of type casts.
diff --git a/src/proto/buffer.pro b/src/proto/buffer.pro
index 91494db..5e1aa7a 100644
--- a/src/proto/buffer.pro
+++ b/src/proto/buffer.pro
@@ -8,7 +8,7 @@
void buf_freeall(buf_T *buf, int flags);
void goto_buffer(exarg_T *eap, int start, int dir, int count);
void handle_swap_exists(bufref_T *old_curbuf);
-char_u *do_bufdel(int command, char_u *arg, int addr_count, int start_bnr, int end_bnr, int forceit);
+char *do_bufdel(int command, char_u *arg, int addr_count, int start_bnr, int end_bnr, int forceit);
int do_buffer(int action, int start, int dir, int count, int forceit);
void set_curbuf(buf_T *buf, int action);
void enter_buffer(buf_T *buf);