Use the correct AVX flags for Windows builds

generate_gypi.sh

 #!/bin/bash -e
 #
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This script is used to generate .gypi, .gni files and files in the
 # config/platform directories needed to build libvpx.
 # Every time libvpx source code is updated just run this script.
 #
@@ skipping 99 matching lines @@
   echo "        ['use_lto==1', {" >> "$2"
   echo "          'cflags!': [" >> "$2"
   echo "            '-flto'," >> "$2"
   echo "            '-ffat-lto-objects'," >> "$2"
   echo "          ]," >> "$2"
   echo "        }]," >> "$2"
   echo "      ]," >> "$2"
   fi
   echo "      'cflags': [ '-m$4', ]," >> "$2"
   echo "      'xcode_settings': { 'OTHER_CFLAGS': [ '-m$4' ] }," >> "$2"
-  if [[ $4 == avx* ]]; then
+  if [[ $4 == avx2 ]]; then
   echo "      'msvs_settings': {" >> "$2"
   echo "        'VCCLCompilerTool': {" >> "$2"
-  echo "          'EnableEnhancedInstructionSet': '3', # /arch:AVX" >> "$2"
+  echo "          'EnableEnhancedInstructionSet': '5', # /arch:AVX2" >> "$2"
   echo "        }," >> "$2"
   echo "      }," >> "$2"
   elif [[ $4 == ssse3 || $4 == sse4.1 ]]; then
   echo "      'conditions': [" >> "$2"
   echo "        ['OS==\"win\" and clang==1', {" >> "$2"
   echo "          # cl.exe's /arch flag doesn't have a setting for SSSE3/4, and cl.exe" >> "$2"
   echo "          # doesn't need it for intrinsics. clang-cl does need it, though." >> "$2"
   echo "          'msvs_settings': {" >> "$2"
   echo "            'VCCLCompilerTool': { 'AdditionalOptions': [ '-m$4' ] }," >> "$2"
   echo "          }," >> "$2"
@@ skipping 379 matching lines @@
 make_clean
 make libvpx_srcs.txt target=libs $config > /dev/null
 convert_srcs_to_project_files libvpx_srcs.txt libvpx_srcs_generic
 
 echo "Remove temporary directory."
 cd $BASE_DIR
 rm -rf $TEMP_DIR
 
 # TODO(fgalligan): Is "--disable-fast-unaligned" needed on mipsel?
 # TODO(fgalligan): Can we turn on "--enable-realtime-only" for mipsel?