To reproduce:
1. Open attached package
2. Open Track scene (if editor doesn't crash, try to build project)
3. Editor crashes (if editor doesn't crash, try to build project)

Reproducible: 2017.3.0a6, 2017.3.0b9, 2018.1.0a4
Not Reproducible: 2017.3.0a5

Stack Trace:

0x0000000142986C79 (Unity) physx::SubSortQuick::sort4
0x00000001429873E2 (Unity) physx::buildFromBounds
0x0000000142987B14 (Unity) physx::RTreeCooker::buildFromTriangles
0x000000014297B20B (Unity) physx::InternalTriangleMeshBuilder::createRTree
0x0000000142970C4D (Unity) physx::TriangleMeshBuilder::loadFromDesc
0x000000014296F72E (Unity) physx::Cooking::loadTriangleMeshDesc
0x000000014296FF42 (Unity) physx::Cooking::createTriangleMesh
0x000000014096F456 (Unity) CreatePxTriangleMeshFromUnityMesh
0x000000014096F811 (Unity) CreatePxMeshFromUnityMesh
0x0000000140971985 (Unity) PhysicsModule::CreateNxMeshFromUnityMesh
0x000000014093C839 (Unity) CollisionMeshData::GetSharedNxMesh
0x0000000140963991 (Unity) MeshCollider::ExtractMeshGeometry
0x0000000140963B1D (Unity) MeshCollider::Create
0x000000014093EDB0 (Unity) Collider::CreatePhysXObjIfNeeded
0x000000014094BB00 (Unity) Collider::AwakeFromLoad