Set Foundation.Data.SubSequence to be RangeReplaceable
Set Foundation.Data.SubSequence to be RangeReplaceable

RangeReplaceableCollection.SubSequence should be a
RangeReplaceableCollection.  Data implements RangeReplaceableCollection,
but sets SubSequence to MutableRandomAccessSlice that is not a
RangeReplaceableCollection.

This commit changes Foundation.Data.SubSequence to
MutableRangeReplaceableRandomAccessSlice.

Fixes rdar://problem/28330713.

IngmarStein/swift,allevato/swift,gregomni/swift,gribozavr/swift,roambotics/swift,uasys/swift,arvedviehweger/swift,JGiola/swift,shajrawi/swift,IngmarStein/swift,huonw/swift,sschiau/swift,jtbandes/swift,deyton/swift,manavgabhawala/swift,milseman/swift,gribozavr/swift,kperryua/swift,tinysun212/swift-windows,tjw/swift,austinzheng/swift,danielmartin/swift,ben-ng/swift,tkremenek/swift,return/swift,amraboelela/swift,lorentey/swift,airspeedswift/swift,swiftix/swift,hughbe/swift,JGiola/swift,parkera/swift,benlangmuir/swift,jopamer/swift,JaSpa/swift,calebd/swift,zisko/swift,modocache/swift,austinzheng/swift,djwbrown/swift,codestergit/swift,benlangmuir/swift,brentdax/swift,gregomni/swift,glessard/swift,arvedviehweger/swift,shahmishal/swift,kstaring/swift,therealbnut/swift,jtbandes/swift,shajrawi/swift,austinzheng/swift,gottesmm/swift,tardieu/swift,glessard/swift,glessard/swift,rudkx/swift,tinysun212/swift-windows,CodaFi/swift,manavgabhawala/swift,brentdax/swift,frootloops/swift,shajrawi/swift,natecook1000/swift,jtbandes/swift,airspeedswift/swift,jmgc/swift,practicalswift/swift,roambotics/swift,gmilos/swift,shahmishal/swift,swiftix/swift,OscarSwanros/swift,JGiola/swift,natecook1000/swift,jtbandes/swift,sschiau/swift,frootloops/swift,rudkx/swift,modocache/swift,therealbnut/swift,JaSpa/swift,arvedviehweger/swift,karwa/swift,alblue/swift,apple/swift,tjw/swift,gribozavr/swift,milseman/swift,gottesmm/swift,sschiau/swift,gregomni/swift,xedin/swift,nathawes/swift,harlanhaskins/swift,stephentyrone/swift,natecook1000/swift,felix91gr/swift,devincoughlin/swift,jckarter/swift,jckarter/swift,xwu/swift,gottesmm/swift,shajrawi/swift,gribozavr/swift,IngmarStein/swift,airspeedswift/swift,tinysun212/swift-windows,stephentyrone/swift,karwa/swift,atrick/swift,felix91gr/swift,tjw/swift,djwbrown/swift,hughbe/swift,atrick/swift,calebd/swift,shahmishal/swift,gribozavr/swift,OscarSwanros/swift,shajrawi/swift,aschwaighofer/swift,gribozavr/swift,calebd/swift,xedin/swift,kstaring/swift,Jnosh/swift,milseman/swift,uasys/swift,tinysun212/swift-windows,felix91gr/swift,sschiau/swift,parkera/swift,ahoppen/swift,arvedviehweger/swift,bitjammer/swift,modocache/swift,devincoughlin/swift,gregomni/swift,felix91gr/swift,jopamer/swift,kstaring/swift,return/swift,lorentey/swift,practicalswift/swift,xwu/swift,JaSpa/swift,uasys/swift,lorentey/swift,OscarSwanros/swift,Jnosh/swift,kperryua/swift,natecook1000/swift,amraboelela/swift,devincoughlin/swift,gottesmm/swift,rudkx/swift,hughbe/swift,therealbnut/swift,OscarSwanros/swift,gmilos/swift,parkera/swift,shahmishal/swift,JGiola/swift,tkremenek/swift,manavgabhawala/swift,karwa/swift,glessard/swift,zisko/swift,aschwaighofer/swift,bitjammer/swift,xwu/swift,harlanhaskins/swift,nathawes/swift,stephentyrone/swift,shahmishal/swift,brentdax/swift,parkera/swift,amraboelela/swift,JGiola/swift,tkremenek/swift,benlangmuir/swift,jmgc/swift,xedin/swift,shahmishal/swift,hooman/swift,djwbrown/swift,hughbe/swift,IngmarStein/swift,IngmarStein/swift,austinzheng/swift,hughbe/swift,return/swift,jopamer/swift,swiftix/swift,JaSpa/swift,CodaFi/swift,ahoppen/swift,frootloops/swift,practicalswift/swift,codestergit/swift,swiftix/swift,natecook1000/swift,jtbandes/swift,tjw/swift,jopamer/swift,danielmartin/swift,shajrawi/swift,jmgc/swift,gmilos/swift,alblue/swift,xedin/swift,bitjammer/swift,hooman/swift,nathawes/swift,airspeedswift/swift,swiftix/swift,calebd/swift,milseman/swift,djwbrown/swift,return/swift,lorentey/swift,xwu/swift,benlangmuir/swift,CodaFi/swift,parkera/swift,aschwaighofer/swift,felix91gr/swift,therealbnut/swift,modocache/swift,deyton/swift,allevato/swift,devincoughlin/swift,atrick/swift,sschiau/swift,zisko/swift,allevato/swift,gottesmm/swift,allevato/swift,practicalswift/swift,jtbandes/swift,xwu/swift,tinysun212/swift-windows,nathawes/swift,deyton/swift,uasys/swift,alblue/swift,swiftix/swift,jopamer/swift,amraboelela/swift,benlangmuir/swift,uasys/swift,jopamer/swift,gottesmm/swift,hooman/swift,devincoughlin/swift,benlangmuir/swift,harlanhaskins/swift,roambotics/swift,milseman/swift,danielmartin/swift,ben-ng/swift,danielmartin/swift,uasys/swift,atrick/swift,kstaring/swift,danielmartin/swift,hooman/swift,Jnosh/swift,codestergit/swift,devincoughlin/swift,gmilos/swift,deyton/swift,codestergit/swift,djwbrown/swift,xedin/swift,JGiola/swift,harlanhaskins/swift,manavgabhawala/swift,gottesmm/swift,stephentyrone/swift,tkremenek/swift,alblue/swift,kperryua/swift,devincoughlin/swift,jckarter/swift,stephentyrone/swift,codestergit/swift,stephentyrone/swift,huonw/swift,xedin/swift,karwa/swift,tardieu/swift,aschwaighofer/swift,Jnosh/swift,ahoppen/swift,gribozavr/swift,uasys/swift,gmilos/swift,amraboelela/swift,natecook1000/swift,bitjammer/swift,xedin/swift,brentdax/swift,danielmartin/swift,manavgabhawala/swift,swiftix/swift,aschwaighofer/swift,nathawes/swift,kstaring/swift,glessard/swift,zisko/swift,JaSpa/swift,sschiau/swift,arvedviehweger/swift,jckarter/swift,tkremenek/swift,rudkx/swift,tjw/swift,deyton/swift,parkera/swift,tjw/swift,kperryua/swift,roambotics/swift,kperryua/swift,kstaring/swift,deyton/swift,kperryua/swift,ahoppen/swift,milseman/swift,jmgc/swift,xwu/swift,felix91gr/swift,aschwaighofer/swift,manavgabhawala/swift,bitjammer/swift,huonw/swift,huonw/swift,jckarter/swift,CodaFi/swift,gregomni/swift,parkera/swift,therealbnut/swift,return/swift,Jnosh/swift,kperryua/swift,devincoughlin/swift,shahmishal/swift,manavgabhawala/swift,hooman/swift,CodaFi/swift,allevato/swift,tjw/swift,aschwaighofer/swift,jtbandes/swift,airspeedswift/swift,IngmarStein/swift,apple/swift,OscarSwanros/swift,return/swift,shajrawi/swift,huonw/swift,huonw/swift,jckarter/swift,arvedviehweger/swift,kstaring/swift,amraboelela/swift,jmgc/swift,brentdax/swift,austinzheng/swift,tinysun212/swift-windows,apple/swift,IngmarStein/swift,jckarter/swift,calebd/swift,ben-ng/swift,alblue/swift,tinysun212/swift-windows,nathawes/swift,zisko/swift,CodaFi/swift,harlanhaskins/swift,lorentey/swift,danielmartin/swift,natecook1000/swift,stephentyrone/swift,harlanhaskins/swift,apple/swift,jopamer/swift,calebd/swift,nathawes/swift,xedin/swift,allevato/swift,djwbrown/swift,ben-ng/swift,brentdax/swift,tkremenek/swift,deyton/swift,codestergit/swift,lorentey/swift,modocache/swift,therealbnut/swift,hooman/swift,Jnosh/swift,karwa/swift,return/swift,amraboelela/swift,bitjammer/swift,xwu/swift,practicalswift/swift,frootloops/swift,milseman/swift,tkremenek/swift,practicalswift/swift,OscarSwanros/swift,felix91gr/swift,jmgc/swift,harlanhaskins/swift,arvedviehweger/swift,calebd/swift,frootloops/swift,lorentey/swift,jmgc/swift,frootloops/swift,therealbnut/swift,lorentey/swift,JaSpa/swift,JaSpa/swift,tardieu/swift,apple/swift,brentdax/swift,allevato/swift,OscarSwanros/swift,shajrawi/swift,roambotics/swift,hughbe/swift,airspeedswift/swift,djwbrown/swift,roambotics/swift,glessard/swift,austinzheng/swift,karwa/swift,bitjammer/swift,CodaFi/swift,atrick/swift,gregomni/swift,atrick/swift,alblue/swift,tardieu/swift,sschiau/swift,gribozavr/swift,modocache/swift,hughbe/swift,frootloops/swift,sschiau/swift,huonw/swift,rudkx/swift,rudkx/swift,ahoppen/swift,tardieu/swift,codestergit/swift,zisko/swift,practicalswift/swift,karwa/swift,tardieu/swift,modocache/swift,gmilos/swift,hooman/swift,parkera/swift,zisko/swift,ben-ng/swift,airspeedswift/swift,ben-ng/swift,shahmishal/swift,alblue/swift,ahoppen/swift,Jnosh/swift,karwa/swift,gmilos/swift,tardieu/swift,ben-ng/swift,austinzheng/swift,apple/swift,practicalswift/swift