Compact persistent and BFGS processes.

Persistent and BFGS processes are large contributors to memory consumption,
but they often need a much smaller working set than they have allocated.
Compact them preemptively to prevent LMKs.

Test: boots, works
bug 125346716
bug 119988524

Change-Id: I20af99e1932c262272388e99b79d12e8f10a1e07