building the mach-o-arm64 target only

[Eric Gorr]

Hello.

I had a question regarding building binutils. I would like to build it
for the mach-o-arm64 target only. If I use the --enable-targets=all
configure option, it will make a copy of objcopy, for example, which
lists mach-o-arm64 as a supported target. However, if I try
--enable-targets=mach-o-arm64 and try to make the project, I get the
error

     BFD does not support target mach-o-arm64.
     Look in bfd/config.bfd for supported targets.

I look at config.bfd, but I am having a great deal of difficulity
parsing that file to figure out how I can get it to build for just the
mach-o-arm64 target. Can anyone help?