I do not think there is anything built in for this. You might be able to check to see is_on_floor
and is_on_ceiling
are both true and if they are, then the KinematicBody is being crushed from the top and bottom. The thing I worry about this is that only one of the two would be set true since the KinematicBody would be pushed through one of the two directions when resolving the physics.
You could also shoot a couple short raycasts in opposite directions and if they both collide then the player is "crushed". If it was me, I'd go for this solution as it may be a bit more consistent.