Sprite execution order incompatibility causes layering issues in this project #2945
Description
Expected Behavior
https://scratch.mit.edu/projects/73724746/ should behave the same in 2.0 and 3.0.
Actual Behavior
This project does not have the mountains in the correct layer when imported into 3.0. I think this is an execution order issue as the sprites follow the model of go to front followed by go back [n] layers. The resulting layer for the sprite in question depends on when the sprites code is executed in comparison to other sprites.
Found by @carljbowman in a smoke test on 08/17/18.