git: kernel - Optimize the x86-64 lwbuf API

[Matthew Dillon]

:
:The optimization is cute, almost devolves this into an assignment, but
:this new API is quite terrible imo, there must be a cleaner way to do
:this.
:
:Sam

    It's not the best API in the world, the lwkt_token code used a
    similar API for a long time (passing the address of a stack-declared
    structure to the functions) which made it more complicated than
    necessary, but I don't think lwkt_token's solution (a per-thread
    array of token pointers) will work for lwbufs.

    Despite the API the actual implementation is ultra fast, even
    for i386 which doesn't use the stack-declared structure.

						-Matt