Actually built a working compiler, the simd stuff still needs a bit of work to function but the compiler works

I modified the simd/simd-real.sig/sml files quite a bit to get them to compile cleanly, I also
modified a bunch of mlb files to reflect removing simd types from the c-types.sml file

I added a file sid/simd.mlb that exports the simd types from the basis library

Finally I worked on the basic tests for the simd functions