Golems cannot be built with Jack-o-lanterns

Put the summary of the bug you're having here
Iron and snow golems can't be built with jack-o-lanterns like they used too.

What I expected to happen was...:
To be able to use a jack-o-lantern to build golems

What actually happened was...:
Instead, it just stayed as blocks. (Note that I did place the jack-o-lanterns last, the way it's supposed to work.)

Steps to Reproduce:
1. Get iron or snow blocks
2. Build a golem with them but instead of using a pumpkin use a jack-o-lantern.
3. This normally works (tested in 1.7.10) but in the snapshots it doesn't. Also, just to mention, using normal pumpkins still works.