Linker shepherd script for L4Re (Fiasco)

Much simplified and explicit CLI for the NVPTX linker. The linker operates with bitcode and uses LLVM backend to generate a PTX assembly.


Linker abstraction used by back::link to build up the command to invoke a linker.


Disables non-English messages from localized linkers. Such messages may cause issues with text encoding on Windows (#35785) and prevent inspection of linker output in case of errors, which we occasionally do. This should be acceptable because other messages from rustc are in English anyway, and may also be desirable to improve searchability of the linker diagnostics.