mksysinfo: Define MADV_ constants for madvise.
mksysinfo: Define MADV_ constants for madvise.

R=iant
CC=gofrontend-dev
https://golang.org/cl/5713052

qskycolor/gofrontend,anlhord/gofrontend,qskycolor/gofrontend,qskycolor/gofrontend,anlhord/gofrontend,qskycolor/gofrontend,qskycolor/gofrontend,anlhord/gofrontend,anlhord/gofrontend,golang/gofrontend,qskycolor/gofrontend,golang/gofrontend,anlhord/gofrontend,qskycolor/gofrontend,golang/gofrontend,golang/gofrontend,anlhord/gofrontend,anlhord/gofrontend