Blender Git Loki

dynamic fracture: fix for depsgraph thread jamming / crashes

the modifier eval thread made calls (validate shard) which changed the rigidbody thread's data from outside, before control is passed to rigidbody thread again (both tasks / threads follow each other alternatingly, first rigidbody, then modifier, then again rigidbody and so on after frames do change. Solution was to delay validation and let the rigidbody thread do it, instead of forcing it from the modifier thread.