Fix android_arm64 target for experimental ndk

BUG=354405
LOG=N
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/233163003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20659 ce2b1a6d-e550-0410-aec6-3dcde31c8c00