Fixes for broadphase/paircache determinism.

Revert definition for ATTRIBUTE_ALIGNED16, and try to force sizeof(btSolverConstraint) by using unions with btScalar, for non-btScalar data types.
Use btAssert and not assert.
Don't access btAlignedObjectArray elements, for zero sets

src/BulletCollision/CollisionShapes/btConeShape.cpp

@@ -60,7 +60,7 @@ void	btConeShape::setConeUpIndex(int upIndex)
 			m_coneIndices[2] = 1;
 		break;
 	default:
-		assert(0);
+		btAssert(0);
 	};
 }