sb-bsd-sockets runtime alien allocation

[Stas Boukarev]

sb-bsd-sockets is doing runtime alien allocation in some places, which causes some functions to be more slow

e.g. (time (sb-bsd-sockets:get-host-by-name "localhost"))

sbcl notes about alien allocation at least in the following functions:
sb-bsd-sockets::make-host-ent
sb-bsd-sockets::get-address-info
sb-bsd-sockets::get-name-info
sb-bsd-sockets::get-protocol-by-name

[Nikodemus Siivola (nikodemus)]

SB-ALIEN in general does a lot of same work again and again when the core optimizations don't kick in.

In the above case, for example, we generate the naturalize-lambda for (UNSIGNED 8) four times during the call.

It seems that cacheing/precomputing the naturalize, deport, deport-alloc, deposit, and extract functions for various types would be a clear win -- particularly when coupled with interning alien types.