ports/171341: multimedia/vlc: Doesn't build with clang

[Juergen Lock]

[Now with the right PR, sorry]

Hm query-pr.cgi doesn't pick up the patch properly, here is it again,
this time against the port dir:

Index: files/patch-include-vlc_common.h
===================================================================
--- files/patch-include-vlc_common.h.orig
+++ files/patch-include-vlc_common.h
@@ -0,0 +1,11 @@
+--- include/vlc_common.h.orig
++++ include/vlc_common.h
+@@ -642,7 +642,7 @@ static inline unsigned popcount (unsigne
+ #endif
+ }
+ 
+-#ifdef __OS2__
++#if defined(__OS2__) || defined(__FreeBSD__)
+ #   undef bswap16
+ #   undef bswap32
+ #   undef bswap64