at install time. This will allow `install -C' to avoid replacing the
installed copy if the new copy is the same. `install -C' would actually
work right if `strip' is already installed, but the Makefile doesn't
know that and has to work for plain `install'.
Stripping should be done by default at link time, but complications
would still be required for installing `strip' in case the default is
overridden.