In setuptools mode, fall back to using pre-built C files if Pyrex hasn't been found
In setuptools mode, fall back to using pre-built C files if Pyrex hasn't been found

GenDataPro/pygr,ctb/pygr,RitwikGupta/pygr,cjlee112/pygr,theoryno3/pygr,GenDataPro/pygr,cjlee112/pygr,ctb/pygr,RitwikGupta/pygr,ctb/pygr,ctb/pygr,cjlee112/pygr,cjlee112/pygr,GenDataPro/pygr,ctb/pygr,RitwikGupta/pygr,theoryno3/pygr,theoryno3/pygr