Auto merge of #85810 - bjorn3:further_driver_cleanup, r=varkor

Driver improvements

This PR contains a couple of cleanups for the driver and a few small improvements for the custom codegen backend interface. It also implements `--version` and `-Cpasses=list` support for custom codegen backends.

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1957,7 +1957,7 @@ fn add_order_independent_options(
     cmd.output_filename(out_filename);
 
     if crate_type == CrateType::Executable && sess.target.is_like_windows {
-        if let Some(ref s) = codegen_results.windows_subsystem {
+        if let Some(ref s) = codegen_results.crate_info.windows_subsystem {
             cmd.subsystem(s);
         }
     }