patch 8.0.0932: terminal may not use right characters for BS and Enter

Problem:    Terminal may not use right characters for BS and Enter.
Solution:   Get the characters from the tty.
diff --git a/src/proto/os_unix.pro b/src/proto/os_unix.pro
index 20765c0..80539d3 100644
--- a/src/proto/os_unix.pro
+++ b/src/proto/os_unix.pro
@@ -50,6 +50,7 @@
 void mch_exit(int r);
 void mch_settmode(int tmode);
 void get_stty(void);
+int get_tty_info(int fd, ttyinfo_T *info);
 void mch_setmouse(int on);
 void check_mouse_termcode(void);
 int mch_screenmode(char_u *arg);