BUG: Fix undefined functions on big-endian systems.
BUG: Fix undefined functions on big-endian systems.

Both these functions are used by `Dragon4_PrintFloat_IEEE_binary128`,
which was recently made available on big-endian systems without these
in #11568.

anntzer/numpy,jorisvandenbossche/numpy,numpy/numpy,pdebuyl/numpy,jakirkham/numpy,mhvk/numpy,seberg/numpy,pbrod/numpy,seberg/numpy,gfyoung/numpy,rgommers/numpy,jorisvandenbossche/numpy,rgommers/numpy,anntzer/numpy,grlee77/numpy,gfyoung/numpy,pizzathief/numpy,mhvk/numpy,seberg/numpy,anntzer/numpy,ahaldane/numpy,shoyer/numpy,numpy/numpy,grlee77/numpy,pizzathief/numpy,ahaldane/numpy,pbrod/numpy,madphysicist/numpy,jakirkham/numpy,WarrenWeckesser/numpy,rgommers/numpy,simongibbons/numpy,charris/numpy,pdebuyl/numpy,madphysicist/numpy,endolith/numpy,mhvk/numpy,madphysicist/numpy,simongibbons/numpy,shoyer/numpy,MSeifert04/numpy,rgommers/numpy,endolith/numpy,jakirkham/numpy,mattip/numpy,numpy/numpy,pbrod/numpy,ahaldane/numpy,jakirkham/numpy,MSeifert04/numpy,madphysicist/numpy,abalkin/numpy,gfyoung/numpy,simongibbons/numpy,pdebuyl/numpy,seberg/numpy,endolith/numpy,mattip/numpy,pbrod/numpy,MSeifert04/numpy,MSeifert04/numpy,charris/numpy,ahaldane/numpy,abalkin/numpy,mattip/numpy,grlee77/numpy,WarrenWeckesser/numpy,pizzathief/numpy,mhvk/numpy,jorisvandenbossche/numpy,anntzer/numpy,pizzathief/numpy,WarrenWeckesser/numpy,pizzathief/numpy,shoyer/numpy,WarrenWeckesser/numpy,pbrod/numpy,mattip/numpy,jorisvandenbossche/numpy,shoyer/numpy,simongibbons/numpy,charris/numpy,numpy/numpy,jorisvandenbossche/numpy,mhvk/numpy,simongibbons/numpy,jakirkham/numpy,grlee77/numpy,ahaldane/numpy,MSeifert04/numpy,grlee77/numpy,abalkin/numpy,endolith/numpy,shoyer/numpy,charris/numpy,pdebuyl/numpy,madphysicist/numpy,WarrenWeckesser/numpy