[llvm] [DXIL] Adding support to RootSignatureFlags in obj2yaml (PR #122396)

[Justin Bogner via llvm-commits]

https://github.com/bogner commented:

This is looking fairly close. A couple of comments in addition to Damyan's here.

Also a couple of notes on the tests:
1. I see you added a compatibility test that used dxil-dis and then removed it citing feedback on the tests. Was there a conversation that I missed? Is there a reason we don't want to add that test?
2. The DXContainerTest also needs some negative test cases - what if the buffer is too small? Do we need to validate that the version is what we expect?

https://github.com/llvm/llvm-project/pull/122396