Add L4Bender as linker variant

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1159,6 +1159,7 @@ pub fn linker_and_flavor(sess: &Session) -> (PathBuf, LinkerFlavor) {
                     LinkerFlavor::Lld(_) => "lld",
                     LinkerFlavor::PtxLinker => "rust-ptx-linker",
                     LinkerFlavor::BpfLinker => "bpf-linker",
+                    LinkerFlavor::L4Bender => "l4-bender",
                 }),
                 flavor,
             )),