Bug 1787319

+++ This bug was initially created as a clone of Bug #1787318 +++

Description of problem:
With the attached scaled configuration if logical-switches are deleted ovn-controller might access freed memory and crash.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Start ovn-northd and point it to the attached northbound db (ovnnb_db.db).
2. Start ovn-controller.
3. Start OVS and bind the logical_switch_ports locally:

for i in $(ovn-nbctl --bare --columns name find logical_switch_port type=\"\"); do
    vm=$(echo $i | cut -f 1 -d "-")
    ovs-vsctl add-port br-int $vm -- set interface $vm type=internal
    ovs-vsctl set interface $vm external_ids:iface-id=$i
done

4. Delete all logical switches:
for s in $(ovn-nbctl list logical_switch | grep -E "^name" | cut -f 2 -d ':' | cut -f 2 -d '"'); do ovn-nbctl ls-del $s; done

Actual results:
ovn-controller might crash:
Program received signal SIGSEGV, Segmentation fault.
0x00000000004b8f47 in hmap_first_with_hash (hmap=hmap@entry=0x91da08, hmap=hmap@entry=0x91da08, hash=2346380341)
    at ./include/openvswitch/hmap.h:328
328         return hmap_next_with_hash__(hmap->buckets[hash & hmap->mask], hash);


Expected results:
ovn-controller shouldn't use memory after it was freed.

Additional info:
Fixed upstream by commits:
2a4965c0e187db0c4218556ed9b06f988e88cb62: ovn-controller: Refactor I-P engine_run() tracking.
5ed53faecef12c09330ced445418c961cb1f8caf: ovn-controller: Add per node states to I-P engine.
2117ba0a91f36206d0f3665e8680c15f1f6fa0a0: ovn-controller: Add separate I-P engine node for processing ct-zones.
94cbc59dc0f1cb56e56d1551956efe5824561864: ovn-controller: Fix use of dangling pointers in I-P runtime_data.