AST: Fix ValueDecl::isUsableFromInline() for destructors
AST: Fix ValueDecl::isUsableFromInline() for destructors

We should make the isUsableFromInline() query a proper request.
For now though, given a DestructorDecl it has to check the class
itself, because we don't always propagate the @usableFromInline
attribute from the class to the destructor.

xedin/swift,harlanhaskins/swift,amraboelela/swift,aschwaighofer/swift,practicalswift/swift,sschiau/swift,roambotics/swift,alblue/swift,jmgc/swift,brentdax/swift,shahmishal/swift,atrick/swift,sschiau/swift,austinzheng/swift,alblue/swift,CodaFi/swift,CodaFi/swift,nathawes/swift,harlanhaskins/swift,glessard/swift,danielmartin/swift,glessard/swift,tkremenek/swift,sschiau/swift,lorentey/swift,karwa/swift,hooman/swift,karwa/swift,practicalswift/swift,nathawes/swift,gribozavr/swift,aschwaighofer/swift,lorentey/swift,jckarter/swift,gribozavr/swift,brentdax/swift,sschiau/swift,airspeedswift/swift,alblue/swift,lorentey/swift,stephentyrone/swift,danielmartin/swift,roambotics/swift,practicalswift/swift,allevato/swift,allevato/swift,apple/swift,shajrawi/swift,jckarter/swift,xwu/swift,ahoppen/swift,austinzheng/swift,shajrawi/swift,shahmishal/swift,karwa/swift,shahmishal/swift,atrick/swift,shahmishal/swift,tkremenek/swift,apple/swift,hooman/swift,xedin/swift,danielmartin/swift,amraboelela/swift,harlanhaskins/swift,stephentyrone/swift,jckarter/swift,jmgc/swift,xwu/swift,tkremenek/swift,aschwaighofer/swift,xedin/swift,apple/swift,sschiau/swift,ahoppen/swift,jckarter/swift,austinzheng/swift,gribozavr/swift,airspeedswift/swift,parkera/swift,tkremenek/swift,alblue/swift,amraboelela/swift,rudkx/swift,stephentyrone/swift,parkera/swift,xwu/swift,hooman/swift,xwu/swift,roambotics/swift,apple/swift,danielmartin/swift,lorentey/swift,allevato/swift,parkera/swift,ahoppen/swift,tkremenek/swift,shajrawi/swift,JGiola/swift,harlanhaskins/swift,airspeedswift/swift,amraboelela/swift,shajrawi/swift,rudkx/swift,gregomni/swift,danielmartin/swift,rudkx/swift,roambotics/swift,benlangmuir/swift,parkera/swift,aschwaighofer/swift,CodaFi/swift,devincoughlin/swift,CodaFi/swift,glessard/swift,gribozavr/swift,gribozavr/swift,austinzheng/swift,practicalswift/swift,xwu/swift,airspeedswift/swift,lorentey/swift,airspeedswift/swift,jmgc/swift,harlanhaskins/swift,parkera/swift,danielmartin/swift,sschiau/swift,gregomni/swift,shajrawi/swift,sschiau/swift,gregomni/swift,lorentey/swift,jckarter/swift,shajrawi/swift,apple/swift,rudkx/swift,stephentyrone/swift,shahmishal/swift,jmgc/swift,amraboelela/swift,benlangmuir/swift,devincoughlin/swift,jmgc/swift,atrick/swift,alblue/swift,allevato/swift,harlanhaskins/swift,devincoughlin/swift,CodaFi/swift,glessard/swift,austinzheng/swift,nathawes/swift,parkera/swift,nathawes/swift,practicalswift/swift,xedin/swift,allevato/swift,aschwaighofer/swift,austinzheng/swift,gregomni/swift,jckarter/swift,xwu/swift,hooman/swift,xedin/swift,gregomni/swift,shahmishal/swift,devincoughlin/swift,shajrawi/swift,devincoughlin/swift,JGiola/swift,lorentey/swift,brentdax/swift,hooman/swift,rudkx/swift,xedin/swift,atrick/swift,nathawes/swift,CodaFi/swift,xedin/swift,sschiau/swift,gregomni/swift,airspeedswift/swift,stephentyrone/swift,jmgc/swift,nathawes/swift,allevato/swift,apple/swift,harlanhaskins/swift,practicalswift/swift,practicalswift/swift,benlangmuir/swift,CodaFi/swift,atrick/swift,shahmishal/swift,gribozavr/swift,JGiola/swift,JGiola/swift,aschwaighofer/swift,shajrawi/swift,parkera/swift,shahmishal/swift,xwu/swift,atrick/swift,karwa/swift,brentdax/swift,practicalswift/swift,JGiola/swift,jmgc/swift,amraboelela/swift,parkera/swift,devincoughlin/swift,ahoppen/swift,ahoppen/swift,JGiola/swift,karwa/swift,gribozavr/swift,benlangmuir/swift,hooman/swift,gribozavr/swift,devincoughlin/swift,rudkx/swift,benlangmuir/swift,karwa/swift,alblue/swift,lorentey/swift,glessard/swift,stephentyrone/swift,ahoppen/swift,devincoughlin/swift,amraboelela/swift,brentdax/swift,xedin/swift,tkremenek/swift,karwa/swift,karwa/swift,danielmartin/swift,jckarter/swift,nathawes/swift,benlangmuir/swift,brentdax/swift,austinzheng/swift,tkremenek/swift,roambotics/swift,allevato/swift,brentdax/swift,alblue/swift,airspeedswift/swift,hooman/swift,stephentyrone/swift,aschwaighofer/swift,glessard/swift,roambotics/swift