Helper function to load object_name from search_dirs.
This function looks in the given directories, and returns the
first VMO matching |object_name| that is found.
parses a config string from the fuchsia.ldsvc.Loader service. See
//docs/concepts/booting/program_loading.md for a description of the format. Returns the set
of directories which should be searched for objects.
start_with_multiple_dirs will expose the fuchsia.ldsvc.Loader service over the given channel,
providing VMO buffers of requested library object names from any of the library directories in
lib_dirs.