The following fixes were required to complete the initial bringup
of the iOS ARM64 Zero Java runtime in the Mobile/dev forest.

1. Change the VAR_CPU_ARCH for 64-bit arm to "arm" from "aarch64.

2. Move the SocketOption and UnixConstant templates into the open JDK repo from closed.

3. Add one more macosx directory for iOS build in the NIO makefile.
Exclude the UTIFileTypeDetector.c file from the iOS build since it
is dependent on a Framework that is not available in iOS. We probably should remove the entire MacOSXFileSystemProvider set of classes.
Currently the default provider for iOS is Bsd.