Goal: get to 100% code coverage for VectorizationBase.jl

[DilumAluthge]

From @chriselrod's comment here:

VectorizationBase.jl also needs a lot more tests. It has <50% coverage at the moment.

For context, here is the current code coverage:

[chriselrod]

I'll try and get it to at least 90%.

I added a help wanted on the off chance there's anyone out there who for some reason enjoys writing unit tests.

[DilumAluthge]

Since VectorizationBase.jl is so important to the LoopVectorization.jl stack, I think it would be good to get to 100% code coverage.

If you can get it to 90%, I can work on the last 10%.

It would also be good to set the 100% goal for the other important packages in the LoopVectorization.jl ecosystem.

[chriselrod]

Sounds like a deal. I don't recall what the coverage was exactly when you filed the issue, but apparently <50%, so I've been making some progress.