[Localization] Add a couple of missing imports
[Localization] Add a couple of missing imports

Import `Path.h` and `FileSystem.h` directly since they are the source
of `llvm::sys::path::extension` and `llvm::system::fs::OpenFlags`
respectively.

Resolves: rdar://77277253

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