[x265] silence VS 2013 warning about g_scan4x4

[Mateusz]

# HG changeset patch
# User Ma0 <mateuszb at poczta.onet.pl>
# Date 1468955593 -7200
#      Tue Jul 19 21:13:13 2016 +0200
# Node ID 88fc302ae8ae5a6191ca6115e371f0777dacc0bb
# Parent  669dc9bfe7ebe40705cc055483d49d82c3fd9977
silence VS 2013 warning about g_scan4x4

diff -r 669dc9bfe7eb -r 88fc302ae8ae source/common/constants.h
--- a/source/common/constants.h    Tue Jul 19 10:33:18 2016 +0530
+++ b/source/common/constants.h    Tue Jul 19 21:13:13 2016 +0200
@@ -81,7 +81,7 @@
 extern const uint16_t* const g_scanOrder[NUM_SCAN_TYPE][NUM_SCAN_SIZE];
 extern const uint16_t* const g_scanOrderCG[NUM_SCAN_TYPE][NUM_SCAN_SIZE];
 extern const uint16_t g_scan8x8diag[8 * 8];
-extern const uint16_t g_scan4x4[NUM_SCAN_TYPE + 1][4 * 4];  // +1 for safe buffer area for codeCoeffNxN assembly optimize, there have up to 15 bytes beyond bound read
+ALIGN_VAR_16(extern const uint16_t, g_scan4x4[NUM_SCAN_TYPE + 1][4 * 4]);  // +1 for safe buffer area for codeCoeffNxN assembly optimize, there have up to 15 bytes beyond bound read
 
 extern const uint8_t g_lastCoeffTable[32];
 extern const uint8_t g_goRiceRange[5]; // maximum value coded with Rice codes