Simplify and memoize specialization__name.
Simplify and memoize specialization__name.

scoder/cython,cython/cython,ChristopherHogan/cython,ChristopherHogan/cython,cython/cython,da-woods/cython,scoder/cython,da-woods/cython,cython/cython,ChristopherHogan/cython,scoder/cython,da-woods/cython,cython/cython,da-woods/cython,scoder/cython