Added js closures test. Fixes #3132.
Added js closures test. Fixes #3132.

russpowers/Nim,zachaysan/Nim,mbaulch/Nim,jfhg/Nim,haiodo/Nim,jfhg/Nim,singularperturbation/Nim,russpowers/Nim,tulayang/Nim,zachaysan/Nim,mbaulch/Nim,jfhg/Nim,singularperturbation/Nim,mbaulch/Nim,mbaulch/Nim,jfhg/Nim,dom96/Nim,zachaysan/Nim,russpowers/Nim,endragor/Nim,endragor/Nim,russpowers/Nim,russpowers/Nim,dom96/Nim,tulayang/Nim,haiodo/Nim,singularperturbation/Nim,singularperturbation/Nim,russpowers/Nim,tulayang/Nim,zachaysan/Nim,endragor/Nim,jfhg/Nim,endragor/Nim,zachaysan/Nim,russpowers/Nim,dom96/Nim,haiodo/Nim,jfhg/Nim,tulayang/Nim,haiodo/Nim,tulayang/Nim,singularperturbation/Nim,mbaulch/Nim,mbaulch/Nim,singularperturbation/Nim,dom96/Nim,dom96/Nim,endragor/Nim,dom96/Nim,tulayang/Nim,endragor/Nim,haiodo/Nim,mbaulch/Nim,haiodo/Nim,singularperturbation/Nim,dom96/Nim,endragor/Nim,zachaysan/Nim,zachaysan/Nim,haiodo/Nim,jfhg/Nim