[llvm] [llvm-objcopy] Always update indirectsymoff in MachO (PR #117726)

[Richard Dzenis via llvm-commits]

RIscRIpt wrote:

> Take a look at obj2yaml - that will allow you to generate the code once and then trim down the MachO binary to the shape that we need for the test.

I didn't know `yaml2obj` exists, thanks!

> Yes, please add the regression tests for this.

I've added a very small test, please see if it's enough.

https://github.com/llvm/llvm-project/pull/117726