Re-add -Wextra
Remove trailing \n\t for last instruction in each asm block
Remove need for aes_state and trailing memcpy

Rather than move the final state into local variable and then memcpy
that to the out variable, directly move to the out variable.
Remove intial memcpy to seed the AES key

Don't copy the key to stack variable. Directly copy the round keys from
the input AES_KEY.