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

[Greg Roth via cfe-commits]

pow2clk wrote:

Closing in light of the above. A new PR will capture the DXIL and SPIRV-specific work

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