[ResultBuilders] Fix a crash in `PreCheckResultBuilderApplication`
[ResultBuilders] Fix a crash in `PreCheckResultBuilderApplication`

Cant assume that `shouldTypeCheckInEnclosingExpression` always
implies a single expression closure anymore.

rudkx/swift,glessard/swift,benlangmuir/swift,JGiola/swift,xwu/swift,roambotics/swift,JGiola/swift,apple/swift,roambotics/swift,roambotics/swift,benlangmuir/swift,rudkx/swift,gregomni/swift,apple/swift,rudkx/swift,ahoppen/swift,JGiola/swift,apple/swift,atrick/swift,ahoppen/swift,xwu/swift,xwu/swift,xwu/swift,atrick/swift,apple/swift,atrick/swift,glessard/swift,xwu/swift,glessard/swift,atrick/swift,apple/swift,glessard/swift,rudkx/swift,benlangmuir/swift,apple/swift,rudkx/swift,atrick/swift,benlangmuir/swift,xwu/swift,atrick/swift,glessard/swift,gregomni/swift,JGiola/swift,JGiola/swift,ahoppen/swift,xwu/swift,gregomni/swift,gregomni/swift,gregomni/swift,ahoppen/swift,roambotics/swift,gregomni/swift,benlangmuir/swift,benlangmuir/swift,ahoppen/swift,roambotics/swift,ahoppen/swift,JGiola/swift,glessard/swift,roambotics/swift,rudkx/swift