[IRGen] Disable pre-specialization for 32-bit ARM on Linux
[IRGen] Disable pre-specialization for 32-bit ARM on Linux

This is a temporary workaround for segfaults we observed in TargetMetadata,
caused by invalid pointers.

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