remove experiments that fail to compile on new nightly

[joonazan]

Removes the module "experiments" because nobody is using it and it breaks compilation.

[shamatar]

Benchmarks depend on them, otherwise I'd remove them immediately

[joonazan]

In that case we can compile this module only for benchmarks, rather than having it be public and always compiled like now. Why do benchmarks need simd when the actual code doesn't, though?

[shamatar]

They do not, but baseline non-vectorized ops are there

[shamatar]

I disabled benchmarks in another PR, just use "main"