Creates an array of type T on the ds with a specified initial length.
Allocates T in the data segment, this will just create T normally for value types.
Resizes a previously allocated array in the data segment to the specified length.
Resizes a previously allocated array in the data segment to the specified length from beneath. New elements will become [0..length] (or removed.)
Very fast and very not thread-safe fixed data segment allocator.