Copper golem can become stuck under shelf blocks

The copper golem can get itself stuck under shelves. This can happen without player intervention.

Repro Steps:

1. Place blocks and a shelf as shown in the attachment

2. Spawn a copper golem, and push it into the corner

Observed Results:

The copper golem is stuck under the shelf, and cannot pathfind away

Expected Results:

The copper golem should not get stuck under the shelf