Sets the C value that a <raw-pointer> points to.
pointer-deref-setter ( (new-val), (kind), (ptr), (offset) )
| new-val | An instance of <object>. The value to set at ptr + offset. |
| kind | A literal <symbol>, one of the C type symbols. The C type expected at ptr + offset. |
| ptr | An instance of <raw-pointer>. |
| offset | An instance of <integer>. A byte offset from the ptr address. |