[clang] [llvm] [HLSL][DXIL][SPIRV] Create llvm dot intrinsic and use for HLSL (PR #102872)

[Nikita Popov via cfe-commits]

https://github.com/nikic requested changes to this pull request.

Please create a separate RFC for these intrinsics. I don't think there is a consensus on these intrinsics, and https://discourse.llvm.org/t/rfc-all-the-math-intrinsics/78294 covers way too much disparate ground (something like "tan" and something like "dot" are entirely separate categories, *especially* if you also want to include integer intrinsics).

https://github.com/llvm/llvm-project/pull/102872