Use raw_ptr methods in message.sw

[AlicanC]

Following up on this: #2828 (comment)

However, the changes you had to send_message seemed a bit buggy. send_message is only tested in token_ops currently so no surprise that Ci was passing. Regardless, I reverted the implementation of send_message to how it was, for the most part. We can iterate on that in the future.

@mohammadfawaz, it seems like raw_ptr::read() didn't behave like I assumed it would. Still made use of ::add() and ::write() to pack alloc()s together and get rid of one __addr_of(), but the other one stayed.

[mohammadfawaz]

Awesome, much better. Thanks!