Slime spawns are incorrect

Slime spawning in slime chunks ignore carpets, path blocks, and blocks filling their spawn radius.

What I expected to happen was...:

When there is something that slimes should not be able to spawn with depending on their spawn area restrictions, they should not be able to spawn. 

What actually happened was...:

Slimes can spawn no matter what is in the way of the spawn chunk.

Steps to Reproduce:

1. Put dirt blocks or carpet in a slime chunk with a grid like pattern of X - - X OR fill a slime chunk with path blocks
2. Leave the area far enough away
3. Slimes will start to spawn no matter what on top of the dirt blocks, carpet, or path blocks