GN: Fix neon files not being included for arm64

BUILD.gn

 # Copyright 2014 The LibYuv 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.
 
 import("//build/config/arm.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
 config("libyuv_config") {
   include_dirs = [
     ".",
     "include",
   ]
 }
 
-use_neon = current_cpu == "arm" && (arm_use_neon || arm_optionally_use_neon)
+use_neon = current_cpu == "arm64" || (current_cpu == "arm" && (arm_use_neon || arm_optionally_use_neon))
 
 source_set("libyuv") {
   sources = [
     "include/libyuv.h",
     "include/libyuv/basic_types.h",
     "include/libyuv/compare.h",
     "include/libyuv/convert.h",
     "include/libyuv/convert_argb.h",
     "include/libyuv/convert_from.h",
     "include/libyuv/convert_from_argb.h",
@@ skipping 88 matching lines @@
       "source/rotate_neon.cc",
       "source/rotate_neon64.cc",
       "source/row_neon.cc",
       "source/row_neon64.cc",
       "source/scale_neon.cc",
       "source/scale_neon64.cc",
     ]
 
     public_configs = [ ":libyuv_config" ]
 
-    configs -= [ "//build/config/compiler:compiler_arm_fpu" ]
-    cflags = [ "-mfpu=neon" ]
+    if (current_cpu != "arm64") {
+      configs -= [ "//build/config/compiler:compiler_arm_fpu" ]
+      cflags = [ "-mfpu=neon" ]
+    }
   }
 }