Flags for the delta object and the file objects on each side.
These flags are used for both the flags value of the git_diff_delta
and the flags for the git_diff_file objects representing the old and
new sides of the delta. Values outside of this public range should be
considered reserved for internal or future use.
file(s) treated as binary data
file(s) treated as text data
id value is known correct
file exists at this side of the delta
file size value is known correct