[llvm] [llvm-readobj][COFF] Add `--coff-output-style` flag (PR #95074)

[Miguel A. Arroyo via llvm-commits]

mayanez wrote:

Thanks for the info @MaskRay ! I've been a bit delayed in opening these as I am still looking into the `spr` workflow to open the stacked PRs.

> While startLine << '\n' is compatible with the JSON output style, most explicit startLine calls are not and need porting.

That's correct. I had to address such cases for this change.

> Yes, --output-style has been discussed a few times now (e.g. when JSON was added https://reviews.llvm.org/D114225).

I think much like as was mentioned previously (and due to the above) it might make sense to do `--coff-output-style` until potentially all formats add JSON support before moving to `--output-style`. Thoughts?

https://github.com/llvm/llvm-project/pull/95074