Imports of splitdwarf command

PathSynopsis
crypto/sha256Package sha256 implements the SHA224 and SHA256 hash algorithms as defined in FIPS 180-4.
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
golang.org/x/tools/cmd/splitdwarf/internal/machoPackage macho implements access to Mach-O object files.
ioPackage io provides basic interfaces to I/O primitives.
osPackage os provides a platform-independent interface to operating system functionality.
path/filepathPackage filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths.
stringsPackage strings implements simple functions to manipulate UTF-8 encoded strings.
syscallPackage syscall contains an interface to the low-level operating system primitives.