[Parser] Delete ASTContext of ParserUnit
[Parser] Delete ASTContext of ParserUnit

This resolves a memory leak.

aschwaighofer/swift,alblue/swift,apple/swift,sschiau/swift,apple/swift,sschiau/swift,shajrawi/swift,tkremenek/swift,practicalswift/swift,xwu/swift,karwa/swift,tkremenek/swift,sschiau/swift,parkera/swift,danielmartin/swift,ahoppen/swift,shajrawi/swift,practicalswift/swift,danielmartin/swift,benlangmuir/swift,airspeedswift/swift,jmgc/swift,lorentey/swift,apple/swift,parkera/swift,sschiau/swift,allevato/swift,hooman/swift,CodaFi/swift,benlangmuir/swift,shajrawi/swift,harlanhaskins/swift,natecook1000/swift,apple/swift,stephentyrone/swift,brentdax/swift,rudkx/swift,karwa/swift,allevato/swift,brentdax/swift,gribozavr/swift,ahoppen/swift,nathawes/swift,benlangmuir/swift,hooman/swift,CodaFi/swift,gregomni/swift,xedin/swift,xedin/swift,ahoppen/swift,shahmishal/swift,parkera/swift,karwa/swift,nathawes/swift,gribozavr/swift,JGiola/swift,airspeedswift/swift,practicalswift/swift,airspeedswift/swift,austinzheng/swift,glessard/swift,danielmartin/swift,harlanhaskins/swift,glessard/swift,harlanhaskins/swift,stephentyrone/swift,gregomni/swift,danielmartin/swift,practicalswift/swift,hooman/swift,ahoppen/swift,devincoughlin/swift,atrick/swift,xedin/swift,lorentey/swift,lorentey/swift,stephentyrone/swift,natecook1000/swift,alblue/swift,atrick/swift,JGiola/swift,jckarter/swift,brentdax/swift,jmgc/swift,devincoughlin/swift,airspeedswift/swift,parkera/swift,hooman/swift,gribozavr/swift,hooman/swift,amraboelela/swift,apple/swift,gregomni/swift,parkera/swift,shajrawi/swift,stephentyrone/swift,jmgc/swift,allevato/swift,ahoppen/swift,sschiau/swift,nathawes/swift,CodaFi/swift,aschwaighofer/swift,jckarter/swift,benlangmuir/swift,jmgc/swift,amraboelela/swift,benlangmuir/swift,practicalswift/swift,sschiau/swift,xedin/swift,devincoughlin/swift,harlanhaskins/swift,austinzheng/swift,rudkx/swift,jckarter/swift,devincoughlin/swift,alblue/swift,devincoughlin/swift,lorentey/swift,gribozavr/swift,allevato/swift,hooman/swift,lorentey/swift,austinzheng/swift,xwu/swift,glessard/swift,xwu/swift,shahmishal/swift,brentdax/swift,benlangmuir/swift,atrick/swift,sschiau/swift,CodaFi/swift,gribozavr/swift,tkremenek/swift,shahmishal/swift,allevato/swift,aschwaighofer/swift,alblue/swift,natecook1000/swift,rudkx/swift,karwa/swift,stephentyrone/swift,practicalswift/swift,gregomni/swift,jmgc/swift,atrick/swift,xwu/swift,danielmartin/swift,aschwaighofer/swift,hooman/swift,amraboelela/swift,brentdax/swift,nathawes/swift,atrick/swift,gribozavr/swift,jckarter/swift,natecook1000/swift,JGiola/swift,jmgc/swift,roambotics/swift,devincoughlin/swift,allevato/swift,harlanhaskins/swift,roambotics/swift,shahmishal/swift,stephentyrone/swift,shajrawi/swift,gregomni/swift,amraboelela/swift,atrick/swift,gribozavr/swift,lorentey/swift,CodaFi/swift,parkera/swift,austinzheng/swift,airspeedswift/swift,harlanhaskins/swift,danielmartin/swift,roambotics/swift,xedin/swift,xwu/swift,CodaFi/swift,sschiau/swift,shajrawi/swift,xedin/swift,shajrawi/swift,aschwaighofer/swift,practicalswift/swift,JGiola/swift,natecook1000/swift,airspeedswift/swift,karwa/swift,allevato/swift,parkera/swift,shahmishal/swift,amraboelela/swift,amraboelela/swift,shajrawi/swift,rudkx/swift,gribozavr/swift,roambotics/swift,airspeedswift/swift,devincoughlin/swift,shahmishal/swift,austinzheng/swift,brentdax/swift,amraboelela/swift,jckarter/swift,lorentey/swift,glessard/swift,aschwaighofer/swift,nathawes/swift,brentdax/swift,apple/swift,tkremenek/swift,natecook1000/swift,alblue/swift,practicalswift/swift,JGiola/swift,karwa/swift,ahoppen/swift,harlanhaskins/swift,karwa/swift,xwu/swift,shahmishal/swift,austinzheng/swift,austinzheng/swift,xedin/swift,xwu/swift,jckarter/swift,rudkx/swift,xedin/swift,lorentey/swift,shahmishal/swift,alblue/swift,danielmartin/swift,glessard/swift,tkremenek/swift,rudkx/swift,jckarter/swift,nathawes/swift,aschwaighofer/swift,glessard/swift,jmgc/swift,roambotics/swift,stephentyrone/swift,roambotics/swift,natecook1000/swift,gregomni/swift,tkremenek/swift,JGiola/swift,tkremenek/swift,karwa/swift,parkera/swift,devincoughlin/swift,nathawes/swift,CodaFi/swift,alblue/swift