clang on linux prefers no args for rep movsl/stosl. ifdef for C that removes namespace.  extern c allows c++ to be used to compile, including with namespace, but C program can link libyuv
BUG=none
TEST=none
Review URL: http://webrtc-codereview.appspot.com/320004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@101 16f28f9a-4ce2-e073-06de-1de4eb20be90
diff --git a/source/rotate_neon.cc b/source/rotate_neon.cc
index 6d8cb47..6ba7d51 100644
--- a/source/rotate_neon.cc
+++ b/source/rotate_neon.cc
@@ -11,7 +11,10 @@
 #include "libyuv/basic_types.h"
 #include "row.h"
 
+#ifdef __cplusplus
 namespace libyuv {
+extern "C" {
+#endif
 
 #if defined(__ARM_NEON__) && !defined(YUV_DISABLE_ASM)
 
@@ -555,4 +558,8 @@
   );
 }
 #endif
-}
+
+#ifdef __cplusplus
+}  // extern "C"
+}  // namespace libyuv
+#endif