[MC-16832] Giants do not get damage when hit by Instant Health

What I excepted to happen was:
Giants get harmed when throwing Instant Health to them. (Because undead get harmed)

What really happened was:
Giants were healed. 😞

Steps to reproduce:
1. Spawn a giant. (Do not ask how)
2. Throw an Instant Health at him!
3. ....
4. Giant did not get harmed or lose health.

Linked issues

Giant is an unsupported mob.

@bljat
Giants are minecraft mob. So this bug is valid.

The fact that you need 3rd party tools to spawn it makes it invalid.

@bljat
I do not care. They are undead, and minecraft developers said that undead mobs get harmed by instant health.

Technically giants aren't undead, they just don't have their own texture, so they use the zombie's.

Giants aren't considered an undead monster, and therefore, must be damaged with an instant damage potion.