MAINT: lib: Move some nested function definitions in loadtxt.
MAINT: lib: Move some nested function definitions in loadtxt.

This change moves the nested function definitions in loadtxt
to the top of the function body.

pbrod/numpy,simongibbons/numpy,grlee77/numpy,madphysicist/numpy,anntzer/numpy,mhvk/numpy,numpy/numpy,rgommers/numpy,anntzer/numpy,simongibbons/numpy,rgommers/numpy,jakirkham/numpy,rgommers/numpy,seberg/numpy,mattip/numpy,charris/numpy,grlee77/numpy,jakirkham/numpy,pbrod/numpy,grlee77/numpy,pdebuyl/numpy,endolith/numpy,jakirkham/numpy,mhvk/numpy,grlee77/numpy,grlee77/numpy,charris/numpy,jakirkham/numpy,madphysicist/numpy,pdebuyl/numpy,simongibbons/numpy,seberg/numpy,madphysicist/numpy,simongibbons/numpy,numpy/numpy,mattip/numpy,numpy/numpy,pbrod/numpy,pdebuyl/numpy,pbrod/numpy,endolith/numpy,pbrod/numpy,mhvk/numpy,mhvk/numpy,mhvk/numpy,seberg/numpy,numpy/numpy,pdebuyl/numpy,charris/numpy,endolith/numpy,madphysicist/numpy,jakirkham/numpy,mattip/numpy,anntzer/numpy,rgommers/numpy,simongibbons/numpy,anntzer/numpy,seberg/numpy,mattip/numpy,madphysicist/numpy,endolith/numpy,charris/numpy