[llvm] [llvm-objcopy] Check for missing argument values (PR #70710)

[Alexey Karyakin via llvm-commits]

quic-akaryaki wrote:

> Are there any options that expect 2+ values (i.e. something that would give a different response to "expected 1 value(s)"? If so, it might be worth switching one of the cases for that one, just for additional bonus coverage without additional test complexity.
> 
> Otherwise, LGTM.

I don't think there are multi-arg options in objcopy. There are some when objcopy is invoked as `llvm-install-name-tool`, but they are handled separately.

https://github.com/llvm/llvm-project/pull/70710