vm_map: drop simplify_entry.9

[dougm]

Summary

A change in 2019 removed the function vm_map_simplify_entry(), but failed
to remove the manual page that documents it. As that was an internal
function not meant to be used outside the kernel, the manual page is
dropped now, and a new manual page for the function that replaced it is
not added.

This diff only shows the changes to other files to stop mentioning the one being dropped. I don't know how to get "Here is a file being removed" into the diff.

Fixes: 83ea714f4fca ("vm_map_simplify_entry considers merging")

[pfg]

"git rm" drops the file from the repo, and should appear somehow in the diff. But if you already did it and it doesn't appear I guess it's OK.

[ziaee]

I think maybe you want to delete the file, then git add it even though it's not there?

[alc]

You should add an entry to ObsoleteFiles.inc.

[dougm]

Update ObsoleteFiles.inc.