MAINT: special: dummy statement for undefined WITH_THREAD (#7861)
MAINT: special: dummy statement for undefined WITH_THREAD (#7861)

If WITH_THREAD is undefined (rare case, yes) then there still must be a statement after the label `skip_warn`, but there is none, 
and one gets a compilation error.
(with `clang-3.8`, I didn't check other compilers, but it is clear from C standard that a statement is needed)
zerothi/scipy,lhilt/scipy,anntzer/scipy,e-q/scipy,jor-/scipy,WarrenWeckesser/scipy,aeklant/scipy,andyfaff/scipy,WarrenWeckesser/scipy,Eric89GXL/scipy,perimosocordiae/scipy,jamestwebber/scipy,perimosocordiae/scipy,tylerjereddy/scipy,matthew-brett/scipy,ilayn/scipy,Stefan-Endres/scipy,jamestwebber/scipy,gfyoung/scipy,jamestwebber/scipy,gfyoung/scipy,zerothi/scipy,jor-/scipy,Stefan-Endres/scipy,e-q/scipy,person142/scipy,mdhaber/scipy,Eric89GXL/scipy,person142/scipy,andyfaff/scipy,grlee77/scipy,anntzer/scipy,aeklant/scipy,andyfaff/scipy,aarchiba/scipy,e-q/scipy,scipy/scipy,scipy/scipy,aarchiba/scipy,scipy/scipy,gfyoung/scipy,gertingold/scipy,aarchiba/scipy,gertingold/scipy,nmayorov/scipy,scipy/scipy,person142/scipy,endolith/scipy,aeklant/scipy,pizzathief/scipy,endolith/scipy,Eric89GXL/scipy,rgommers/scipy,lhilt/scipy,tylerjereddy/scipy,ilayn/scipy,gfyoung/scipy,Eric89GXL/scipy,gfyoung/scipy,pizzathief/scipy,andyfaff/scipy,perimosocordiae/scipy,jamestwebber/scipy,person142/scipy,scipy/scipy,matthew-brett/scipy,endolith/scipy,endolith/scipy,rgommers/scipy,grlee77/scipy,rgommers/scipy,aeklant/scipy,zerothi/scipy,mdhaber/scipy,Eric89GXL/scipy,tylerjereddy/scipy,gertingold/scipy,tylerjereddy/scipy,nmayorov/scipy,nmayorov/scipy,WarrenWeckesser/scipy,aarchiba/scipy,Stefan-Endres/scipy,arokem/scipy,perimosocordiae/scipy,ilayn/scipy,anntzer/scipy,jor-/scipy,perimosocordiae/scipy,vigna/scipy,lhilt/scipy,person142/scipy,matthew-brett/scipy,e-q/scipy,gertingold/scipy,lhilt/scipy,arokem/scipy,vigna/scipy,aeklant/scipy,grlee77/scipy,rgommers/scipy,WarrenWeckesser/scipy,grlee77/scipy,ilayn/scipy,e-q/scipy,vigna/scipy,Stefan-Endres/scipy,matthew-brett/scipy,ilayn/scipy,andyfaff/scipy,vigna/scipy,nmayorov/scipy,nmayorov/scipy,jor-/scipy,matthew-brett/scipy,rgommers/scipy,zerothi/scipy,anntzer/scipy,anntzer/scipy,pizzathief/scipy,endolith/scipy,aarchiba/scipy,anntzer/scipy,perimosocordiae/scipy,pizzathief/scipy,vigna/scipy,mdhaber/scipy,mdhaber/scipy,grlee77/scipy,lhilt/scipy,Eric89GXL/scipy,endolith/scipy,ilayn/scipy,jamestwebber/scipy,gertingold/scipy,andyfaff/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,mdhaber/scipy,arokem/scipy,arokem/scipy,Stefan-Endres/scipy,zerothi/scipy,WarrenWeckesser/scipy,pizzathief/scipy,arokem/scipy,zerothi/scipy,scipy/scipy,jor-/scipy,tylerjereddy/scipy,mdhaber/scipy