Add NDK r10, arm64-v8a, x86_64, mips64 support.

ANDROID_NDK_ABI_NAME is used for locating libs, such as sources\cxx-stl\gnu-libstdc++\4.9\libs\x86_64\libgnustl_static.a in NDK r10. At least in here, it's x86_64. So we may need 2 variables, one "x86_64" and one "x86-64". AWWW.