Deterministic simulation for concave and compound collision shapes: added childShapeA/B to b3Contact4 + sort on them

Use tetrahedra instead of barrel for convex demo (until performance for edge-edge is improved)
Increased #overlapping pair capacity from 12 to 16 / objec

src/Bullet3OpenCL/RigidBody/kernels/solverUtils.cl

@@ -389,6 +389,12 @@ typedef struct
 
 	int m_bodyAPtrAndSignBit;
 	int m_bodyBPtrAndSignBit;
+
+	int	m_childIndexA;
+	int	m_childIndexB;
+	int m_unused1;
+	int m_unused2;
+
 } Contact4;