Add a test for empty path in CanonicalizePath().
Add a test for empty path in CanonicalizePath().

This test covers bug fix introduced by 62e9139740.  However,
reverting this patch does not trigger a test failure.  Maybe, I am
not testing on the right platform (Linux).  Anyway, in all cases
I think this test deserves to be added.

pck/ninja,nicolasdespres/ninja,kissthink/ninja,dabrahams/ninja,mutac/ninja,okuoku/ninja,ehird/ninja,purcell/ninja,PetrWolf/ninja,synaptek/ninja,mdempsky/ninja,sgraham/ninja,metti/ninja,ukai/ninja,mydongistiny/ninja,rjogrady/ninja,jhanssen/ninja,Ju2ender/ninja,rjogrady/ninja,nickhutchinson/ninja,jsternberg/ninja,drbo/ninja,syntheticpp/ninja,atetubou/ninja,okuoku/ninja,sxlin/dist_ninja,ndsol/subninja,nico/ninja,dorgonman/ninja,dendy/ninja,sxlin/dist_ninja,ignatenkobrain/ninja,Ju2ender/ninja,ninja-build/ninja,ignatenkobrain/ninja,maruel/ninja,AoD314/ninja,purcell/ninja,nocnokneo/ninja,jhanssen/ninja,Qix-/ninja,AoD314/ninja,Qix-/ninja,SByer/ninja,fifoforlifo/ninja,rnk/ninja,dendy/ninja,fifoforlifo/ninja,sxlin/dist_ninja,ctiller/ninja,pck/ninja,maximuska/ninja,vvvrrooomm/ninja,synaptek/ninja,mutac/ninja,rnk/ninja,jendrikillner/ninja,kissthink/ninja,mgaunard/ninja,tfarina/ninja,LuaDist/ninja,ninja-build/ninja,sxlin/dist_ninja,tfarina/ninja,ilor/ninja,guiquanz/ninja,bmeurer/ninja,okuoku/ninja,ilor/ninja,ukai/ninja,yannicklm/ninja,Maratyszcza/ninja-pypi,rnk/ninja,syntheticpp/ninja,lizh06/ninja,fifoforlifo/ninja,purcell/ninja,jendrikillner/ninja,martine/ninja,dabrahams/ninja,okuoku/ninja,nafest/ninja,pathscale/ninja,mohamed/ninja,glensc/ninja,tfarina/ninja,sorbits/ninja,dorgonman/ninja,ikarienator/ninja,ninja-build/ninja,dabrahams/ninja,martine/ninja,automeka/ninja,Ju2ender/ninja,mohamed/ninja,mydongistiny/ninja,tychoish/ninja,martine/ninja,fuchsia-mirror/third_party-ninja,kimgr/ninja,glensc/ninja,automeka/ninja,yannicklm/ninja,synaptek/ninja,AoD314/ninja,lizh06/ninja,lizh06/ninja,jsternberg/ninja,dpwright/ninja,iwadon/ninja,ikarienator/ninja,mdempsky/ninja,tychoish/ninja,synaptek/ninja,ignatenkobrain/ninja,mathstuf/ninja,mathstuf/ninja,ukai/ninja,jhanssen/ninja,PetrWolf/ninja-main,curinir/ninja,nickhutchinson/ninja,Maratyszcza/ninja-pypi,nafest/ninja,sorbits/ninja,metti/ninja,moroten/ninja,jsternberg/ninja,PetrWolf/ninja-main,colincross/ninja,mohamed/ninja,colincross/ninja,bradking/ninja,moroten/ninja,nocnokneo/ninja,drbo/ninja,mathstuf/ninja,ctiller/ninja,hnney/ninja,kissthink/ninja,glensc/ninja,mgaunard/ninja,hnney/ninja,sgraham/ninja,dendy/ninja,maruel/ninja,nicolasdespres/ninja,Maratyszcza/ninja-pypi,ctiller/ninja,mutac/ninja,guiquanz/ninja,nafest/ninja,maruel/ninja,jendrikillner/ninja,autopulated/ninja,ehird/ninja,atetubou/ninja,dpwright/ninja,hnney/ninja,drbo/ninja,iwadon/ninja,pathscale/ninja,PetrWolf/ninja-main,jimon/ninja,TheOneRing/ninja,dabrahams/ninja,pck/ninja,moroten/ninja,mydongistiny/ninja,sxlin/dist_ninja,chenyukang/ninja,chenyukang/ninja,metti/ninja,SByer/ninja,LuaDist/ninja,mdempsky/ninja,dendy/ninja,barak/ninja,barak/ninja,PetrWolf/ninja-main,bmeurer/ninja,curinir/ninja,ndsol/subninja,dpwright/ninja,bmeurer/ninja,mydongistiny/ninja,ThiagoGarciaAlves/ninja,chenyukang/ninja,drbo/ninja,ignatenkobrain/ninja,jimon/ninja,syntheticpp/ninja,PetrWolf/ninja,maruel/ninja,ilor/ninja,mathstuf/ninja,TheOneRing/ninja,nickhutchinson/ninja,ilor/ninja,PetrWolf/ninja,dpwright/ninja,vvvrrooomm/ninja,kimgr/ninja,ThiagoGarciaAlves/ninja,rjogrady/ninja,jimon/ninja,mohamed/ninja,moroten/ninja,pathscale/ninja,curinir/ninja,mgaunard/ninja,LuaDist/ninja,automeka/ninja,curinir/ninja,metti/ninja,lizh06/ninja,maximuska/ninja,barak/ninja,glensc/ninja,fuchsia-mirror/third_party-ninja,nico/ninja,yannicklm/ninja,guiquanz/ninja,SByer/ninja,nickhutchinson/ninja,sgraham/ninja,bradking/ninja,juntalis/ninja,ninja-build/ninja,nocnokneo/ninja,kissthink/ninja,nocnokneo/ninja,pathscale/ninja,ndsol/subninja,fifoforlifo/ninja,Qix-/ninja,bradking/ninja,autopulated/ninja,nicolasdespres/ninja,mgaunard/ninja,dorgonman/ninja,sxlin/dist_ninja,tfarina/ninja,autopulated/ninja,sorbits/ninja,jimon/ninja,barak/ninja,mdempsky/ninja,pck/ninja,kimgr/ninja,colincross/ninja,vvvrrooomm/ninja,guiquanz/ninja,maximuska/ninja,tychoish/ninja,bmeurer/ninja,fuchsia-mirror/third_party-ninja,ctiller/ninja,juntalis/ninja,martine/ninja,bradking/ninja,vvvrrooomm/ninja,jhanssen/ninja,nico/ninja,SByer/ninja,sgraham/ninja,ikarienator/ninja,kimgr/ninja,ThiagoGarciaAlves/ninja,autopulated/ninja,fuchsia-mirror/third_party-ninja,iwadon/ninja,Ju2ender/ninja,PetrWolf/ninja,ikarienator/ninja,chenyukang/ninja,TheOneRing/ninja,automeka/ninja,syntheticpp/ninja,jsternberg/ninja,ndsol/subninja,liukd/ninja,mutac/ninja,ukai/ninja,rnk/ninja,LuaDist/ninja,sorbits/ninja,sxlin/dist_ninja,atetubou/ninja,nafest/ninja,liukd/ninja,nicolasdespres/ninja,rjogrady/ninja,liukd/ninja,Qix-/ninja,hnney/ninja,AoD314/ninja,dorgonman/ninja,iwadon/ninja,ehird/ninja,nico/ninja,juntalis/ninja,Maratyszcza/ninja-pypi,tychoish/ninja,TheOneRing/ninja,jendrikillner/ninja,colincross/ninja,juntalis/ninja,atetubou/ninja,maximuska/ninja,liukd/ninja,ThiagoGarciaAlves/ninja,yannicklm/ninja,purcell/ninja,ehird/ninja