kern/47158: __HAVE_TOPDOWN_VM has bit-rotted

[christos%zoulas.com@localhost]

>Number:         47158
>Category:       kern
>Synopsis:       __HAVE_TOPDOWN_VM has bit-rotted
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Nov 03 21:55:00 +0000 2012
>Originator:     Christos Zoulas
>Release:        NetBSD 6.99.14
>Organization:
        Roach Breeders, Inc.
>Environment:
NetBSD quasar.astron.com 6.99.14 NetBSD 6.99.14 (QUASAR) #251: Tue Oct 23 
12:02:03 EDT 2012  
christos%quasar.astron.com@localhost:/usr/src/sys/arch/amd64/compile/QUASAR 
amd64

Architecture: x86_64
Machine: amd64
>Description:
        Sometime ago, perhaps around the time that the i386/amd64 pmap merge,
        topdown vm support was deleted. Please put it back because it is
        useful on 32 bit ports
>How-To-Repeat:
        grep -r __HAVE_TOPDOWN_VM /usr/src/sys

>Fix:
        ?