Avoid slow `abs_dirname()` by loading `realpath` extension
Avoid slow `abs_dirname()` by loading `realpath` extension

This speeds up every `rbenv` invocation significantly.

beck/rbenv,syndbg/goenv,takluyver/pyenv,syndbg/goenv,obimod/pyenv,bradynpoulsen/rbenv,yogeshkakde/rbenv,reyesyang/rbenv,pyenv/pyenv,adarshmuthappa/nodenv,jmatbastos/rbenv,nodenv/nodenv,yeonsh/pyenv,howtolearntocode/rbenv,pyenv/pyenv,jasonkarns/rbenv,Ferocia/rbenv,syndbg/goenv,stivenrgalvis/rbenv,lozybean/pyenv,viclim/rbenv,cehoffman/rbenv,jmatbastos/rbenv,viclim/rbenv,genome-vendor/pyenv,cyril/rbenv,josegonzalez/rbenv,pyenv/pyenv,Angeldude/rbenv,OiNutter/nodenv,cyril/rbenv,rridhan/rbenv,dnsd/pyenv,peterpih/rbenv,SamuraiT/rbenv,hlecuanda/pyenv,stivenrgalvis/rbenv,lozybean/pyenv,takluyver/pyenv,jasonkarns/rbenv,jeremy/rbenv,VShangxiao/pyenv,michael-gabenna/rbenv,pumpkineater/rbenv,jmatbastos/rbenv,yogeshkakde/rbenv,zmwangx/pyenv,jasonkarns/rbenv,cehoffman/rbenv,cehoffman/pyenv,jrolfs/nodenv,jmatbastos/rbenv,recruit-mtl/pyenv,Angeldude/rbenv,rowhit/pyenv,SamuraiT/rbenv,dnsd/pyenv,sstephenson/rbenv,michael-gabenna/rbenv,xshwy/pyenv,princeofdarkness76/rbenv,reyesyang/rbenv,RinSer/rbenv,princeofdarkness76/rbenv,codesdk/rbenv,dark5un/nodenv,lozybean/rbenv,bradynpoulsen/rbenv,sebhahn/pyenv,andrew-christianson/rbenv,intfrr/rbenv,janusnic/rbenv,SamuraiT/rbenv,rridhan/rbenv,rbenv/rbenv,viclim/rbenv,intfrr/rbenv,RinSer/rbenv,jeremy/rbenv,howtolearntocode/rbenv,sstephenson/rbenv,janusnic/rbenv,docwhat/rbenv,dark5un/nodenv,princeofdarkness76/rbenv,reyesyang/rbenv,yyyc514/rbenv,intfrr/rbenv,rbenv/rbenv,avdhoweb/rbenv,chenfengyuan/pyenv,dongguangming/pyenv,recruit-mtl/pyenv,andrew-christianson/rbenv,cehoffman/luaenv,mediadoneright/rbenv,jmatbastos/rbenv,rridhan/rbenv,stivenrgalvis/rbenv,jeongdeoksu/rbenv,UCASREN/pyenv,dongguangming/pyenv,chenfengyuan/pyenv,RinSer/rbenv,beck/rbenv,syndbg/goenv,BanzaiMan/pyenv,jmatbastos/rbenv,lozybean/rbenv,pumpkineater/rbenv,bradynpoulsen/rbenv,yyyc514/rbenv,adarshmuthappa/nodenv,beck/rbenv,cehoffman/luaenv,docwhat/rbenv,josegonzalez/rbenv,avdhoweb/rbenv,VShangxiao/pyenv,andrew-christianson/rbenv,obimod/pyenv,rowhit/pyenv,cyril/rbenv,howtolearntocode/rbenv,codesdk/rbenv,codesdk/rbenv,Ferocia/rbenv,yeonsh/pyenv,yyyc514/rbenv,peterpih/rbenv,jrolfs/nodenv,UCASREN/pyenv,josegonzalez/rbenv,cehoffman/pyenv,hlecuanda/pyenv,janusnic/rbenv,BanzaiMan/pyenv,mediadoneright/rbenv,mediadoneright/rbenv,peterpih/rbenv,habinmusic/pyenv,jeremy/rbenv,lozybean/rbenv,sebhahn/pyenv,genome-vendor/pyenv,Angeldude/rbenv,yyuu/pyenv,yyuu/pyenv,fly19890211/pyenv,fly19890211/pyenv,jeongdeoksu/rbenv,pumpkineater/rbenv,xshwy/pyenv,OiNutter/nodenv,yogeshkakde/rbenv,nodenv/nodenv,jmatbastos/rbenv,sebhahn/pyenv,cehoffman/nodenv,habinmusic/pyenv,docwhat/rbenv,Ferocia/rbenv,zmwangx/pyenv,jeongdeoksu/rbenv,avdhoweb/rbenv,michael-gabenna/rbenv,cehoffman/rbenv,sstephenson/rbenv,cehoffman/nodenv