Blender Git Loki

Limit Rotation: explicitly orthogonalize the matrix before processing.

Add a call to orthogonalize the matrix before processing for the
same reasons as D8915, and an early exit in case no limits are
enabled for a bit of extra efficiency.

Since the constraint goes through Euler decomposition, it would
in fact remove shear even before this change, but the resulting
rotation won't make much sense.

This change allows using the constraint without any enabled limits
purely for the purpose of efficiently removing shear.

Differential Revision: https://developer.blender.org/D9626