Iron Golems cannot be created underwater

When trying to make an Iron Golem underwater, it doesn't spawn.

Steps to Reproduce:

1. Try to make an Iron Golem underwater

Observed Results:
The Iron Golem does not spawn.

Expected Results:
The Iron Golem should be able to spawn.

Notes:
Snow Golems can be spawned underwater.

This bug does not Work as Intended, because MC-60792 was reopened.

Even when the water is removed the Iron Golem still does not spawn.