Add a [rtc_]build_with_neon variable to unify conditions.

webrtc/modules/audio_processing/audio_processing.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.
 
 {
   'variables': {
@@ skipping 164 matching lines @@
             'ns/include/noise_suppression.h',
             'ns/noise_suppression.c',
             'ns/ns_core.c',
             'ns/ns_core.h',
             'ns/windows_private.h',
           ],
         }],
         ['target_arch=="ia32" or target_arch=="x64"', {
           'dependencies': ['audio_processing_sse2',],
         }],
-        ['(target_arch=="arm" and arm_version>=7) or target_arch=="arm64"', {
+        ['build_with_neon==1', {
           'dependencies': ['audio_processing_neon',],
         }],
         ['target_arch=="mipsel" and mips_arch_variant!="r6"', {
           'sources': [
             'aecm/aecm_core_mips.c',
           ],
           'conditions': [
             ['mips_float_abi=="hard"', {
               'sources': [
                 'aec/aec_core_mips.c',
@@ skipping 42 matching lines @@
             ['os_posix==1', {
               'cflags': [ '-msse2', ],
               'xcode_settings': {
                 'OTHER_CFLAGS': [ '-msse2', ],
               },
             }],
           ],
         },
       ],
     }],
-    ['(target_arch=="arm" and arm_version>=7) or target_arch=="arm64"', {
+    ['build_with_neon==1', {
       'targets': [{
         'target_name': 'audio_processing_neon',
         'type': 'static_library',
         'includes': ['../../build/arm_neon.gypi',],
         'dependencies': [
           '<(webrtc_root)/common_audio/common_audio.gyp:common_audio',
         ],
         'sources': [
           'aec/aec_core_neon.c',
           'aec/aec_rdft_neon.c',
           'aecm/aecm_core_neon.c',
           'ns/nsx_core_neon.c',
         ],
-        'conditions': [
-          # Disable LTO in audio_processing_neon target due to compiler bug
-          ['use_lto==1', {
-            'cflags!': [
-              '-flto',
-              '-ffat-lto-objects',
-            ],
-          }],
-        ],
       }],
     }],
   ],
 }