patch 8.0.1531: cannot use 24 bit colors in MS-Windows console

Problem:    Cannot use 24 bit colors in MS-Windows console.
Solution:   Add support for vcon. (Nobuhiro Takasaki, Ken Takasaki,
            fixes #1270, fixes #2060)
diff --git a/src/proto/os_win32.pro b/src/proto/os_win32.pro
index a87d8b7..d76e270 100644
--- a/src/proto/os_win32.pro
+++ b/src/proto/os_win32.pro
@@ -42,6 +42,7 @@
 void mch_new_shellsize(void);
 void mch_set_winsize_now(void);
 int mch_call_shell(char_u *cmd, int options);
+void win32_build_env(dict_T *env, garray_T *gap, int is_terminal);
 void mch_job_start(char *cmd, job_T *job, jobopt_T *options);
 char *mch_job_status(job_T *job);
 job_T *mch_detect_ended_job(job_T *job_list);
@@ -67,5 +68,7 @@
 void set_alist_count(void);
 void fix_arg_enc(void);
 int mch_setenv(char *var, char *value, int x);
-void win32_build_env(dict_T *l, garray_T *gap, int is_terminal);
+void control_console_color_rgb(void);
+int has_vtp_working(void);
+int use_vtp(void);
 /* vim: set ft=c : */