LLVM Minix changes

- import libcxx
 - reduce targets to the one when compiled as a tools

Change-Id: Iabb8427f80ff8e89463559a28bcb8b4f2bdbc496

sbin/mknod/mknod.c

@@ -331,6 +331,9 @@ callPack(pack_t *f, int n, u_long *numbers)
 
 #ifdef KERN_DRIVERS
 static void
+#if defined(__minix)
+__dead
+#endif /* defined(__minix) */
 get_device_info(void)
 {
 #if defined(__minix)

sbin/newfs_ext2fs/newfs_ext2fs.c

@@ -130,7 +130,9 @@ static char *disktype = NULL;
 #endif /* !defined(__minix) */
 static char device[MAXPATHLEN];
 
+#if !defined(__minix)
 static const char lmsg[] = "%s: can't read disk label";
+#endif /* !defined(__minix) */
 
 int
 main(int argc, char *argv[])