libvpx: Pull from upstream

source/libvpx/vpx_ports/msvc.h

Index: source/libvpx/vpx_ports/msvc.h
diff --git a/source/libvpx/vpx_dsp/vpx_dsp_rtcd.c b/source/libvpx/vpx_ports/msvc.h
similarity index 65%
copy from source/libvpx/vpx_dsp/vpx_dsp_rtcd.c
copy to source/libvpx/vpx_ports/msvc.h
index 5fe27b614bdcd7be4df2ea700f16190d1258ab27..43a36e761841c367cb6d84ec8fc49b5851f646f5 100644
--- a/source/libvpx/vpx_dsp/vpx_dsp_rtcd.c
+++ b/source/libvpx/vpx_ports/msvc.h
@@ -7,11 +7,16 @@
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
+
+#ifndef VPX_PORTS_MSVC_H_
+#define VPX_PORTS_MSVC_H_
+#ifdef _MSC_VER
+
 #include "./vpx_config.h"
-#define RTCD_C
-#include "./vpx_dsp_rtcd.h"
-#include "vpx_ports/vpx_once.h"
 
-void vpx_dsp_rtcd() {
-  once(setup_rtcd_internal);
-}
+# if _MSC_VER < 1900  // VS2015 provides snprintf
+#  define snprintf _snprintf
+# endif  // _MSC_VER < 1900
+
+#endif  // _MSC_VER
+#endif  // VPX_PORTS_MSVC_H_