[llvm] [DirectX] Add `extract-section` to `llvm-objcopy` and implement it for `DXContainer` (PR #154804)

[James Henderson via llvm-commits]

https://github.com/jh7370 commented:

Please don't force push to branches under active review as it impairs the reviewing experience (and consequenetly is against LLVM policy). If rebasing is needed, do a merge from the branch you want to update to. The merge commit will disappear when you Squash & Merge).

https://github.com/llvm/llvm-project/pull/154804