[clang] [llvm] [DXIL] implement dot intrinsic lowering for integers (PR #85662)

[Farzon Lotfi via cfe-commits]

farzonl wrote:

> Also failing on http://45.33.8.238/linux/133623/step_7.txt
> 
> It's been broken for over an hour now. Time to revert and fix async?

I have a PR up to fix this, but I would be equally happy with just adding an XFAIL to SemaHLSL/BuiltIns/dot-errors.hlsl if you feel like my PR would take to long to land. 

https://github.com/llvm/llvm-project/pull/85662