introduce android_x64 build target

Makefile

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 216 matching lines @@
 # - "clean": clean all ARCHES
 
 # ----------------- internal stuff ------------------------
 
 # Architectures and modes to be compiled. Consider these to be internal
 # variables, don't override them (use the targets instead).
 ARCHES = ia32 x64 x32 arm arm64 mips mipsel mips64el x87 ppc ppc64
 DEFAULT_ARCHES = ia32 x64 arm
 MODES = release debug optdebug
 DEFAULT_MODES = release debug
-ANDROID_ARCHES = android_ia32 android_arm android_arm64 android_mipsel android_x87
+ANDROID_ARCHES = android_ia32 android_x64 android_arm android_arm64 \
+                 android_mipsel android_x87
 NACL_ARCHES = nacl_ia32 nacl_x64
 
 # List of files that trigger Makefile regeneration:
 GYPFILES = third_party/icu/icu.gypi third_party/icu/icu.gyp \
            build/shim_headers.gypi build/features.gypi build/standalone.gypi \
            build/toolchain.gypi build/all.gyp build/mac/asan.gyp \
            build/android.gypi test/cctest/cctest.gyp \
            test/unittests/unittests.gyp tools/gyp/v8.gyp \
            tools/parser-shell.gyp testing/gmock.gyp testing/gtest.gyp \
            buildtools/third_party/libc++abi/libc++abi.gyp \
@@ skipping 242 matching lines @@
 # We need to manually set the stack limit here, to work around bugs in
 # gmake-3.81 and global-5.7.1 on recent 64-bit Linux systems.
 GPATH GRTAGS GSYMS GTAGS: gtags.files $(shell cat gtags.files 2> /dev/null)
         @bash -c 'ulimit -s 10240 && GTAGSFORCECPP=yes gtags -i -q -f $<'
 
 gtags.clean:
         rm -f gtags.files GPATH GRTAGS GSYMS GTAGS
 
 dependencies builddeps:
         $(error Use 'gclient sync' instead)