Using `HalfSpace` collider shape stalls broad phase in rapier3d-f64

[jsatka]

Using HalfSpace collider shape in rapier3d-f64 (on a fixed rigid body) leads to three nested loops, each covering range of i32::MIN .. i32::MAX in the broad phase collision detection (of the first physics timestep) here:

rapier/src/geometry/broad_phase_multi_sap/sap_layer.rs

Lines 223 to 234 in 053cb22

	let start = super::point_key(aabb_to_discretize.mins, self.region_width);
	let end = super::point_key(aabb_to_discretize.maxs, self.region_width);
	// Discretize the aabb.
	#[cfg(feature = "dim2")]
	let k_range = 0..1;
	#[cfg(feature = "dim3")]
	let k_range = start.z..=end.z;
	for i in start.x..=end.x {
	for j in start.y..=end.y {
	for _k in k_range.clone() {

Halfspace collider shape AABB half extents are always 0.5 * Real::MAX, and thus the start and end variables in the above referenced lines end up equaling Point<i32>::min_value() and Point<i32>::max_value() with halfspaces.

The issue can seemingly be fixed by changing the constant in

rapier/src/geometry/broad_phase_multi_sap/sap_utils.rs

Line 6 in aaf80bf

pub(crate) const SENTINEL_VALUE: Real = Real::MAX;

to

pub(crate) const SENTINEL_VALUE: Real = f32::MAX as Real;

but I am unsure about potential unwanted possible side-effects of the change in other use cases and if better approaches to fix the issue exist. More educated thoughts on the fix would be most welcome!