Blender Git Loki

Fix T60185: Crash on adding Inverse Kinematics

When having loops in a kinematic chain and also a IK constrain,
the solve_cycle function removes graph relations necessary to ensure
the cleanup operation was running at the very end.

Due to his Blender was crashing when some operations (the bone
constraints) accessed a pointer that was already freed.

Solved by adding more relations between crucial nodes.