add a dedicated test for .pxd overrides in pure mode
add a dedicated test for .pxd overrides in pure mode

fperez/cython,fabianrost84/cython,slonik-az/cython,mcanthony/cython,c-blake/cython,scoder/cython,scoder/cython,da-woods/cython,achernet/cython,ABcDexter/cython,acrispin/cython,acrispin/cython,hickford/cython,madjar/cython,mrGeen/cython,encukou/cython,ABcDexter/cython,da-woods/cython,dahebolangkuan/cython,c-blake/cython,fabianrost84/cython,roxyboy/cython,andreasvc/cython,slonik-az/cython,fabianrost84/cython,JelleZijlstra/cython,c-blake/cython,dahebolangkuan/cython,ChristopherHogan/cython,JelleZijlstra/cython,andreasvc/cython,mrGeen/cython,dahebolangkuan/cython,cython/cython,mrGeen/cython,achernet/cython,JelleZijlstra/cython,dahebolangkuan/cython,madjar/cython,fperez/cython,da-woods/cython,acrispin/cython,fabianrost84/cython,ABcDexter/cython,hhsprings/cython,marscher/cython,encukou/cython,hickford/cython,c-blake/cython,fperez/cython,slonik-az/cython,da-woods/cython,fabianrost84/cython,mcanthony/cython,achernet/cython,hhsprings/cython,roxyboy/cython,hhsprings/cython,roxyboy/cython,encukou/cython,mcanthony/cython,marscher/cython,cython/cython,encukou/cython,ChristopherHogan/cython,acrispin/cython,andreasvc/cython,dahebolangkuan/cython,scoder/cython,hickford/cython,mrGeen/cython,hickford/cython,hhsprings/cython,JelleZijlstra/cython,hickford/cython,mcanthony/cython,ChristopherHogan/cython,c-blake/cython,slonik-az/cython,JelleZijlstra/cython,madjar/cython,fperez/cython,ABcDexter/cython,mrGeen/cython,madjar/cython,hhsprings/cython,andreasvc/cython,achernet/cython,cython/cython,slonik-az/cython,marscher/cython,fperez/cython,mcanthony/cython,ABcDexter/cython,scoder/cython,marscher/cython,marscher/cython,cython/cython,roxyboy/cython,encukou/cython,achernet/cython,acrispin/cython,roxyboy/cython,madjar/cython,andreasvc/cython