[llvm] [DXIL][Analysis] Implement enough of DXILResourceAnalysis for buffers (PR #100699)

[Justin Bogner via llvm-commits]

bogner wrote:

> Sorry, I had to revert to unbreak the bots for now, but feel free to reland with the fix!

No need to apologize, thanks for getting trunk back to green. Oddly I don't seem to have gotten any emails from bots for these particular failures...

https://github.com/llvm/llvm-project/pull/100699