CpuMath Enhancement: Add Debug.Assert to check matching lengths of arguments to SSE/AVX intrinsics

[briancylui]

Style changes needed to solve part of https://github.com/dotnet/machinelearning/issues/823

Details

• In src\Microsoft.ML.CpuMath\SseIntrinsics.cs, it may make sense to add some Debug.Asserts to check the src and dst Lengths match. However, these are internal functions that are only called from functions that guarantee the arguments are checked, so it might not be a blocking issue. It just may be some nice documentation on the expectations of these methods. And in case they get new callsites in the future.

[TomFinley]

However, these are internal functions that are only called from functions that guarantee the arguments are checked, so it might not be a blocking issue.

This is not a reason not to do it. Asserts are only called from debug anyway, so there is no question of them having user facing impact. They are for detecting whether we have bugs internally. (If there were any chance of them being called outside they should be checks.)