bvi: -Werror=implicit-function-declaration

packages/bvi/comm.c.patch

@@ -0,0 +1,15 @@
+diff -u -r ../bvi-1.4.0/comm.c ./comm.c
+--- ../bvi-1.4.0/comm.c	2014-01-29 14:54:53.000000000 +0000
++++ ./comm.c	2017-07-07 07:11:55.310380582 +0000
+@@ -84,10 +84,10 @@
+ extern	char	*name;			/* actual filename */
+ extern	char	**files;		/* used for "next" and "rewind" */
+ extern	int		numfiles, curfile;
+-extern	int		errno;
+ 
+ static	char	oldbuf[CMDSZ];		/** for :!! command **/
+ 
++int save_chk(char* fname, char* start, char* end, int flags);
+ 
+ /*
+  * docmdline() - handle a colon command

packages/bvi/fix_errno.patch

@@ -1,20 +0,0 @@
---- bvi-1.4.0/bm_unix.c	2013-08-25 11:59:33.000000000 -0700
-+++ src/bm_unix.c	2017-02-19 00:34:01.618869104 -0800
-@@ -260,7 +260,6 @@
- vgetc()
- {
-     char cha;
--    extern int errno;
- 
-     errno = 0;
-     if (read(2, &cha, 1) <= 0) {
---- bvi-1.4.0/comm.c	2014-01-29 06:54:53.000000000 -0800
-+++ src/comm.c	2017-02-19 00:34:01.622869129 -0800
-@@ -84,7 +84,6 @@
- extern	char	*name;			/* actual filename */
- extern	char	**files;		/* used for "next" and "rewind" */
- extern	int		numfiles, curfile;
--extern	int		errno;
- 
- static	char	oldbuf[CMDSZ];		/** for :!! command **/
-