pmap_advise() + bug fix for ARMv6/v7

[Zbigniew Bodek]

Hello,

I would like to present two, new patches for pmap-v6, available here:
http://people.freebsd.org/~zbb/arm/pmap/

* 0001-Write-protect-base-page-after-superpage-demotion-so-.patch
  - bug fix for attributes modification after superpage demotion so that it
could repromote on
    a subsequent write access.
* 0002-Implement-pmap_advise-for-ARMv6-v7-pmap-module.patch
  - implementation of the pmap_advise() routine

I will appreciate if you could test those patches on your ARM-based
machines and send your feedback. Any remarks are also welcome :)

In case of no objections I will write to re@ for permission to commit them.

Best regards
Zbyszek