Replaces current basis function calculation which seems to be a direct
implementation of the recursive NURBS formulation. New implementation
avoids the need to check for zero divisions during iteration. Out of
bounds checks are also converted to asserts, assuming input provides
valid span index.
Performance wise this nets a 7+% performance improvement with the
average result being as fast or faster then the fastest execution
from previous implementation!
Pull Request: https://projects.blender.org/blender/blender/pulls/144457