[build-script] Re-enable lldb unit tests in PR testing.
[build-script] Re-enable lldb unit tests in PR testing.

This have been disabled because they were flakey, but now we
should have fixed the issues (or if there's something outstanding,
well, it's the right time to fix).

This is getting more important as we want to increase the set
of `lit/` or `unittest`-style testcases.

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