Add a [rtc_]build_with_neon variable to unify conditions.

webrtc/modules/audio_coding/codecs/isac/isacfix.gypi

 # Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 {
   'targets': [
@@ skipping 71 matching lines @@
         }],
         ['target_arch=="arm" and arm_version>=7', {
           'sources': [
             'fix/source/lattice_armv7.S',
             'fix/source/pitch_filter_armv6.S',
           ],
           'sources!': [
             'fix/source/lattice_c.c',
             'fix/source/pitch_filter_c.c',
           ],
-          'conditions': [
-            ['arm_neon==1 or arm_neon_optional==1', {
-              'dependencies': [ 'isac_neon' ],
-            }],
-          ],
         }],
-        ['target_arch=="arm64"', {
+        ['build_with_neon==1', {
           'dependencies': ['isac_neon', ],
         }],
         ['target_arch=="mipsel" and mips_arch_variant!="r6"', {
           'sources': [
             'fix/source/entropy_coding_mips.c',
             'fix/source/filters_mips.c',
             'fix/source/lattice_mips.c',
             'fix/source/pitch_estimator_mips.c',
             'fix/source/transform_mips.c',
           ],
@@ skipping 15 matching lines @@
               'sources!': [
                 'fix/source/pitch_filter_c.c',
               ],
             }],
           ],
         }],
       ],
     },
   ],
   'conditions': [
-    ['target_arch=="arm" and arm_version>=7 or target_arch=="arm64"', {
+    ['build_with_neon==1', {
       'targets': [
         {
           'target_name': 'isac_neon',
           'type': 'static_library',
           'includes': ['../../../../build/arm_neon.gypi',],
           'dependencies': [
             '<(webrtc_root)/common_audio/common_audio.gyp:common_audio',
           ],
           'sources': [
             'fix/source/entropy_coding_neon.c',
             'fix/source/filters_neon.c',
             'fix/source/lattice_neon.c',
             'fix/source/transform_neon.c',
           ],
           'conditions': [
-            # Disable LTO in isac_neon target due to compiler bug
-            ['use_lto==1', {
-              'cflags!': [
-                '-flto',
-                '-ffat-lto-objects',
-              ],
-            }],
             # Disable AllpassFilter2FixDec16Neon function due to a clang
             # bug. Refer more details at:
             # https://code.google.com/p/webrtc/issues/detail?id=4567
             ['target_arch!="arm64" or clang==0', {
-                  'sources': ['fix/source/filterbanks_neon.c',],
+              'sources': ['fix/source/filterbanks_neon.c',],
             }]
           ],
         },
       ],
     }],
   ],
 }