Fix build on i386.

ok sthen@

graphics/openimageio/patches/patch-src_libutil_tbb_misc_cpp

@@ -0,0 +1,11 @@
+$OpenBSD: patch-src_libutil_tbb_misc_cpp,v 1.1 2013/05/23 20:51:51 pascal Exp $
+--- src/libutil/tbb_misc.cpp.orig	Thu May 23 20:49:22 2013
++++ src/libutil/tbb_misc.cpp	Thu May 23 20:52:25 2013
+@@ -111,6 +111,7 @@ extern "C" int TBB_runtime_interface_version() {
+ #if __TBB_x86_32
+ 
+ #include "tbb/atomic.h"
++#include "tbb/tbb_assert_impl.h"
+ 
+ // in MSVC environment, int64_t defined in tbb::internal namespace only (see tbb_stddef.h)
+ #if _MSC_VER