MAINT: tweak cython variables declarations to avoid the warning
'Non-trivial type declarators in shared declaration ...' that is
generated by cython 0.20.
MAINT: special: tweak the generated cython variable declarations in _ufuncs.pyx
to avoid the warning 'Non-trivial type declarators in shared declaration ...'
that is generated by cython 0.20.
GEN: special: regenerate _ufuncs.pyx
Merge pull request #3430 from WarrenWeckesser/cython-declarations

MAINT: Fix some cython variable declarations to avoid warnings with cython 0.20.