Revert "[XFail] Disable Runtime/linux-fatal-backtrace (55490694)"
Revert "[XFail] Disable Runtime/linux-fatal-backtrace (55490694)"

This reverts commit 76915b2db1c567d9d1581532158f08b9e4cb7bc5.

atrick/swift,apple/swift,aschwaighofer/swift,jmgc/swift,jmgc/swift,jckarter/swift,stephentyrone/swift,JGiola/swift,JGiola/swift,tkremenek/swift,karwa/swift,gribozavr/swift,airspeedswift/swift,apple/swift,lorentey/swift,devincoughlin/swift,aschwaighofer/swift,gregomni/swift,lorentey/swift,xwu/swift,karwa/swift,CodaFi/swift,benlangmuir/swift,CodaFi/swift,hooman/swift,lorentey/swift,gregomni/swift,gribozavr/swift,hooman/swift,benlangmuir/swift,nathawes/swift,nathawes/swift,apple/swift,benlangmuir/swift,lorentey/swift,tkremenek/swift,benlangmuir/swift,devincoughlin/swift,lorentey/swift,rudkx/swift,gregomni/swift,aschwaighofer/swift,nathawes/swift,JGiola/swift,roambotics/swift,stephentyrone/swift,devincoughlin/swift,harlanhaskins/swift,lorentey/swift,parkera/swift,ahoppen/swift,sschiau/swift,glessard/swift,parkera/swift,tkremenek/swift,nathawes/swift,parkera/swift,jmgc/swift,tkremenek/swift,atrick/swift,CodaFi/swift,jmgc/swift,gregomni/swift,karwa/swift,karwa/swift,aschwaighofer/swift,xwu/swift,nathawes/swift,gregomni/swift,roambotics/swift,parkera/swift,sschiau/swift,harlanhaskins/swift,stephentyrone/swift,hooman/swift,CodaFi/swift,gribozavr/swift,xwu/swift,ahoppen/swift,stephentyrone/swift,sschiau/swift,jckarter/swift,atrick/swift,devincoughlin/swift,ahoppen/swift,glessard/swift,gregomni/swift,rudkx/swift,devincoughlin/swift,karwa/swift,karwa/swift,parkera/swift,sschiau/swift,devincoughlin/swift,tkremenek/swift,stephentyrone/swift,roambotics/swift,apple/swift,parkera/swift,devincoughlin/swift,jckarter/swift,airspeedswift/swift,atrick/swift,atrick/swift,allevato/swift,allevato/swift,jckarter/swift,roambotics/swift,xwu/swift,gribozavr/swift,JGiola/swift,xwu/swift,harlanhaskins/swift,CodaFi/swift,airspeedswift/swift,CodaFi/swift,JGiola/swift,gribozavr/swift,harlanhaskins/swift,lorentey/swift,sschiau/swift,airspeedswift/swift,harlanhaskins/swift,gribozavr/swift,parkera/swift,airspeedswift/swift,nathawes/swift,hooman/swift,allevato/swift,allevato/swift,hooman/swift,roambotics/swift,jckarter/swift,jckarter/swift,ahoppen/swift,CodaFi/swift,harlanhaskins/swift,JGiola/swift,stephentyrone/swift,roambotics/swift,atrick/swift,jckarter/swift,gribozavr/swift,karwa/swift,lorentey/swift,sschiau/swift,karwa/swift,glessard/swift,sschiau/swift,rudkx/swift,glessard/swift,apple/swift,parkera/swift,xwu/swift,allevato/swift,devincoughlin/swift,benlangmuir/swift,tkremenek/swift,rudkx/swift,nathawes/swift,ahoppen/swift,rudkx/swift,xwu/swift,rudkx/swift,ahoppen/swift,glessard/swift,jmgc/swift,aschwaighofer/swift,benlangmuir/swift,allevato/swift,stephentyrone/swift,hooman/swift,jmgc/swift,gribozavr/swift,hooman/swift,tkremenek/swift,allevato/swift,sschiau/swift,jmgc/swift,airspeedswift/swift,aschwaighofer/swift,apple/swift,aschwaighofer/swift,harlanhaskins/swift,glessard/swift,airspeedswift/swift