[stdlib] Fix conversion from Float16 to unsigned integer types (#36219)
[stdlib] Fix conversion from Float16 to unsigned integer types (#36219)

* [stdlib] Fix conversion from Float16 to unsigned integer types

* [stdlib] Tighten up concrete Float16-to-integer conversions
JGiola/swift,glessard/swift,rudkx/swift,hooman/swift,benlangmuir/swift,JGiola/swift,xwu/swift,apple/swift,parkera/swift,JGiola/swift,atrick/swift,rudkx/swift,rudkx/swift,apple/swift,parkera/swift,gregomni/swift,hooman/swift,rudkx/swift,hooman/swift,apple/swift,ahoppen/swift,parkera/swift,xwu/swift,gregomni/swift,roambotics/swift,roambotics/swift,JGiola/swift,benlangmuir/swift,benlangmuir/swift,parkera/swift,tkremenek/swift,JGiola/swift,benlangmuir/swift,glessard/swift,tkremenek/swift,tkremenek/swift,atrick/swift,tkremenek/swift,atrick/swift,parkera/swift,parkera/swift,xwu/swift,atrick/swift,rudkx/swift,benlangmuir/swift,apple/swift,hooman/swift,hooman/swift,tkremenek/swift,roambotics/swift,glessard/swift,gregomni/swift,parkera/swift,glessard/swift,rudkx/swift,gregomni/swift,glessard/swift,xwu/swift,parkera/swift,JGiola/swift,xwu/swift,xwu/swift,ahoppen/swift,xwu/swift,tkremenek/swift,hooman/swift,ahoppen/swift,gregomni/swift,roambotics/swift,roambotics/swift,atrick/swift,roambotics/swift,ahoppen/swift,tkremenek/swift,ahoppen/swift,ahoppen/swift,apple/swift,apple/swift,glessard/swift,hooman/swift,atrick/swift,benlangmuir/swift,gregomni/swift