Its possible to create SIMD vector at runtime

# exmaple form matrix multiplication

struct Vector[vector_size:Int]:
    var data:DTypePointer[DType.float32]

    fn __init__(inout self):
        self.data = DTypePointer[DType.float32].alloc(vector_size)
        memset_zero(self.data, vector_size)

    fn load[nelts: Int](self, x: Int) -> SIMD[DType.float32, nelts]:
        return self.data.load[width=nelts](x)

    fn store[nelts: Int](self, x: Int, val: SIMD[DType.float32, nelts]):
        return self.data.store[width=nelts](x, val)

    fn __getitem__(self, x: Int) -> Scalar[DType.float32]:
        return self.load[1](x)

    fn __setitem__(self, x: Int, val: Scalar[DType.float32]):
        self.store[1](x, val)

var score = Vector[corpus_size]() # error