Allow paths to be buffers in fs of node v6.x (#9359)
Allow paths to be buffers in fs of node v6.x (#9359)

* Allow buffers to be passed in fs for node v6.x

* Fix wrongly typed index in fs.realpath

Fixes the following errors:
- node.d.ts(1426,62): error TS1023: An index signature parameter type must be 'string' or 'number'.
- node.d.ts(1427,68): error TS1023: An index signature parameter type must be 'string' or 'number'.

arusakov/DefinitelyTyped,gcastre/DefinitelyTyped,magny/DefinitelyTyped,EnableSoftware/DefinitelyTyped,AbraaoAlves/DefinitelyTyped,damianog/DefinitelyTyped,subash-a/DefinitelyTyped,alexdresko/DefinitelyTyped,benishouga/DefinitelyTyped,paulmorphy/DefinitelyTyped,magny/DefinitelyTyped,alvarorahul/DefinitelyTyped,chrismbarr/DefinitelyTyped,nycdotnet/DefinitelyTyped,amanmahajan7/DefinitelyTyped,raijinsetsu/DefinitelyTyped,psnider/DefinitelyTyped,raijinsetsu/DefinitelyTyped,markogresak/DefinitelyTyped,dsebastien/DefinitelyTyped,danfma/DefinitelyTyped,aciccarello/DefinitelyTyped,nycdotnet/DefinitelyTyped,use-strict/DefinitelyTyped,abbasmhd/DefinitelyTyped,arusakov/DefinitelyTyped,tan9/DefinitelyTyped,mattblang/DefinitelyTyped,sledorze/DefinitelyTyped,syuilo/DefinitelyTyped,isman-usoh/DefinitelyTyped,arusakov/DefinitelyTyped,psnider/DefinitelyTyped,DzmitryDulko/DefinitelyTyped,daptiv/DefinitelyTyped,schmuli/DefinitelyTyped,tan9/DefinitelyTyped,schmuli/DefinitelyTyped,gandjustas/DefinitelyTyped,mcrawshaw/DefinitelyTyped,alexdresko/DefinitelyTyped,georgemarshall/DefinitelyTyped,abbasmhd/DefinitelyTyped,GiedriusGrabauskas/DefinitelyTyped,arma-gast/DefinitelyTyped,minodisk/DefinitelyTyped,zuzusik/DefinitelyTyped,mattblang/DefinitelyTyped,martinduparc/DefinitelyTyped,hellopao/DefinitelyTyped,paulmorphy/DefinitelyTyped,amanmahajan7/DefinitelyTyped,one-pieces/DefinitelyTyped,ashwinr/DefinitelyTyped,frogcjn/DefinitelyTyped,martinduparc/DefinitelyTyped,Penryn/DefinitelyTyped,GiedriusGrabauskas/DefinitelyTyped,borisyankov/DefinitelyTyped,florentpoujol/DefinitelyTyped,johan-gorter/DefinitelyTyped,arma-gast/DefinitelyTyped,borisyankov/DefinitelyTyped,Litee/DefinitelyTyped,Litee/DefinitelyTyped,jraymakers/DefinitelyTyped,georgemarshall/DefinitelyTyped,sledorze/DefinitelyTyped,martinduparc/DefinitelyTyped,rcchen/DefinitelyTyped,AgentME/DefinitelyTyped,EnableSoftware/DefinitelyTyped,micurs/DefinitelyTyped,xStrom/DefinitelyTyped,mcrawshaw/DefinitelyTyped,YousefED/DefinitelyTyped,rolandzwaga/DefinitelyTyped,benishouga/DefinitelyTyped,jimthedev/DefinitelyTyped,musicist288/DefinitelyTyped,nainslie/DefinitelyTyped,Zzzen/DefinitelyTyped,nainslie/DefinitelyTyped,slavomirvojacek/adbrain-typescript-definitions,ashwinr/DefinitelyTyped,schmuli/DefinitelyTyped,georgemarshall/DefinitelyTyped,AgentME/DefinitelyTyped,smrq/DefinitelyTyped,minodisk/DefinitelyTyped,slavomirvojacek/adbrain-typescript-definitions,frogcjn/DefinitelyTyped,scriby/DefinitelyTyped,chrootsu/DefinitelyTyped,Ptival/DefinitelyTyped,psnider/DefinitelyTyped,newclear/DefinitelyTyped,damianog/DefinitelyTyped,johan-gorter/DefinitelyTyped,shlomiassaf/DefinitelyTyped,smrq/DefinitelyTyped,subash-a/DefinitelyTyped,donnut/DefinitelyTyped,aciccarello/DefinitelyTyped,hellopao/DefinitelyTyped,QuatroCode/DefinitelyTyped,zuzusik/DefinitelyTyped,syuilo/DefinitelyTyped,aciccarello/DefinitelyTyped,laurentiustamate94/DefinitelyTyped,jimthedev/DefinitelyTyped,YousefED/DefinitelyTyped,progre/DefinitelyTyped,slavomirvojacek/DefinitelyTyped,pocesar/DefinitelyTyped,donnut/DefinitelyTyped,AgentME/DefinitelyTyped,newclear/DefinitelyTyped,mhegazy/DefinitelyTyped,zuzusik/DefinitelyTyped,AbraaoAlves/DefinitelyTyped,mhegazy/DefinitelyTyped,alvarorahul/DefinitelyTyped,chrootsu/DefinitelyTyped,chrismbarr/DefinitelyTyped,mcliment/DefinitelyTyped,HPFOD/DefinitelyTyped,pocesar/DefinitelyTyped,slavomirvojacek/DefinitelyTyped,rolandzwaga/DefinitelyTyped,scriby/DefinitelyTyped,use-strict/DefinitelyTyped,shlomiassaf/DefinitelyTyped,florentpoujol/DefinitelyTyped,yuit/DefinitelyTyped,hellopao/DefinitelyTyped,DzmitryDulko/DefinitelyTyped,gcastre/DefinitelyTyped,isman-usoh/DefinitelyTyped,rcchen/DefinitelyTyped,QuatroCode/DefinitelyTyped,abner/DefinitelyTyped,progre/DefinitelyTyped,jimthedev/DefinitelyTyped,benliddicott/DefinitelyTyped,Penryn/DefinitelyTyped,abner/DefinitelyTyped,amir-arad/DefinitelyTyped,AgentME/DefinitelyTyped,axelcostaspena/DefinitelyTyped,jraymakers/DefinitelyTyped,pocesar/DefinitelyTyped,HPFOD/DefinitelyTyped,benishouga/DefinitelyTyped,gandjustas/DefinitelyTyped,AbraaoAlves/DefinitelyTyped,danfma/DefinitelyTyped,georgemarshall/DefinitelyTyped,Ptival/DefinitelyTyped,yuit/DefinitelyTyped,xStrom/DefinitelyTyped,Zzzen/DefinitelyTyped,dsebastien/DefinitelyTyped