add -fvisibility=hidden to CC flags, mark XXX_main functions
EXTERNALLY_VISIBLE. 5% size reduction of libbusybox.so

diff --git a/miscutils/mountpoint.c b/miscutils/mountpoint.c
index 376bd95..5647e4c 100644
--- a/miscutils/mountpoint.c
+++ b/miscutils/mountpoint.c
@@ -11,7 +11,7 @@
 
 #include "libbb.h"
 
-int mountpoint_main(int argc, char **argv);
+int mountpoint_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int mountpoint_main(int argc, char **argv)
 {
 	struct stat st;