The documentation and help messages have recommended the double-dash forms for
quite a while. Remove one-dash long options which are not recognized by GNU
style `getopt_long`.
`-arch` is kept as it is in the manpage of classic nm
https://keith.github.io/xcode-man-pages/nm.1.html
Note: the dyldinfo related options don't have a test.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D105948