Fix libvpx's gyp for enabling AVX instructions with MSVC and clang-cl

third_party/libvpx_new/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 151 matching lines @@
   echo "      ]," >> "$2"
   echo "      'cflags': [ '-m$4', ]," >> "$2"
   echo "      'asmflags': [ '-m$4', ]," >> "$2"
   else
   echo "      'cflags': [ '-m$4', ]," >> "$2"
   echo "      'xcode_settings': { 'OTHER_CFLAGS': [ '-m$4' ] }," >> "$2"
   fi
   if [[ -z $DISABLE_AVX && $4 == avx ]]; then
   echo "      'msvs_settings': {" >> "$2"
   echo "        'VCCLCompilerTool': {" >> "$2"
-  echo "          'EnableEnhancedInstructionSet': '4', # /arch:AVX" >> "$2"
+  echo "          'EnableEnhancedInstructionSet': '3', # /arch:AVX" >> "$2"
   echo "        }," >> "$2"
   echo "      }," >> "$2"
   fi
   if [[ -z $DISABLE_AVX && $4 == avx2 ]]; then
   echo "      'msvs_settings': {" >> "$2"
   echo "        'VCCLCompilerTool': {" >> "$2"
   echo "          'EnableEnhancedInstructionSet': '5', # /arch:AVX2" >> "$2"
   echo "        }," >> "$2"
   echo "      }," >> "$2"
   fi
@@ skipping 411 matching lines @@
 gn format --in-place $BASE_DIR/libvpx_srcs.gni
 
 cd $BASE_DIR/$LIBVPX_SRC_DIR
 echo
 echo "Update README.chromium:"
 git log -1 --format="%cd%nCommit: %H" --date=format:"Date: %A %B %d %Y"
 
 cd $BASE_DIR
 
 # TODO(fgalligan): Can we turn on "--enable-realtime-only" for mipsel?