Remove bitcode_llvm_cmdline

It used to be necessary on Apple platforms to ship with the App Store,
but XCode 15 has stopped embedding LLVM bitcode and the App Store no
longer accepts apps with bitcode embedded.

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -99,7 +99,6 @@ pub struct ModuleConfig {
     pub emit_obj: EmitObj,
     pub emit_thin_lto: bool,
     pub emit_thin_lto_summary: bool,
-    pub bc_cmdline: String,
 
     // Miscellaneous flags. These are mostly copied from command-line
     // options.
@@ -216,7 +215,6 @@ impl ModuleConfig {
                 sess.opts.output_types.contains_key(&OutputType::ThinLinkBitcode),
                 false
             ),
-            bc_cmdline: sess.target.bitcode_llvm_cmdline.to_string(),
 
             verify_llvm_ir: sess.verify_llvm_ir(),
             lint_llvm_ir: sess.opts.unstable_opts.lint_llvm_ir,