Re: splay tree and red-black tree for vm_map entry lookups.

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

    Whoops.  There's something wrong with your hint patch.  My buildworld
    died horribly on a seg-fault and on other issues.  Also, I think the
    hint-setting optimization you made is broken.  You can't just set it to 
    entry->prev if the vm_map_lookup_entry() fails because first_entry
    could be pointing to the last entry in the list causing entry to point
    at &map->header and then the hint would point at the first entry in the
    list, which is probably wrong.

    I am continuing to test your non-hint patch with a buildworld loop.  Once
    I'm sure it works properly I will revisit the hinting code.

					-Matt