pid maps: add limited support for updatable maps
in turns, this allow to use mmap() random writing when restoring int->pid maps
Test Plan
pytest
Migrated from D1970 (view on Phabricator)
Staging instance, all changes can be removed at any time
in turns, this allow to use mmap() random writing when restoring int->pid maps
pytest
Migrated from D1970 (view on Phabricator)