Update cmake/modules/AddSwift.cmake
Update cmake/modules/AddSwift.cmake

Use `SEND_ERROR` instead of `FATAL_ERROR`.

Co-authored-by: Saleem Abdulrasool <d3629432f14a71b62e796d32d075121c69cf67de@compnerd.org>
gregomni/swift,glessard/swift,rudkx/swift,hooman/swift,tkremenek/swift,benlangmuir/swift,apple/swift,ahoppen/swift,tkremenek/swift,JGiola/swift,apple/swift,roambotics/swift,roambotics/swift,atrick/swift,parkera/swift,xwu/swift,hooman/swift,benlangmuir/swift,JGiola/swift,atrick/swift,benlangmuir/swift,parkera/swift,benlangmuir/swift,apple/swift,tkremenek/swift,parkera/swift,roambotics/swift,rudkx/swift,benlangmuir/swift,hooman/swift,parkera/swift,roambotics/swift,xwu/swift,gregomni/swift,rudkx/swift,rudkx/swift,tkremenek/swift,hooman/swift,xwu/swift,hooman/swift,benlangmuir/swift,xwu/swift,atrick/swift,gregomni/swift,roambotics/swift,glessard/swift,parkera/swift,atrick/swift,apple/swift,JGiola/swift,ahoppen/swift,apple/swift,gregomni/swift,gregomni/swift,glessard/swift,xwu/swift,JGiola/swift,ahoppen/swift,ahoppen/swift,atrick/swift,hooman/swift,rudkx/swift,parkera/swift,gregomni/swift,glessard/swift,roambotics/swift,xwu/swift,xwu/swift,rudkx/swift,hooman/swift,JGiola/swift,parkera/swift,JGiola/swift,tkremenek/swift,parkera/swift,ahoppen/swift,tkremenek/swift,atrick/swift,tkremenek/swift,glessard/swift,apple/swift,glessard/swift,ahoppen/swift