Rollup merge of #121194 - beetrees:rustc-raw-args, r=petrochenkov

Refactor pre-getopts command line argument handling

Rebased version of #111658. I've also fixed the Windows CI failure (although I don't have access to Windows to test it myself).

compiler/rustc_driver_impl/src/lib.rs

@@ -292,7 +292,7 @@ fn run_compiler(
     // the compiler with @empty_file as argv[0] and no more arguments.
     let at_args = at_args.get(1..).unwrap_or_default();
 
-    let args = args::arg_expand_all(&default_early_dcx, at_args);
+    let args = args::arg_expand_all(&default_early_dcx, at_args)?;
 
     let Some(matches) = handle_options(&default_early_dcx, &args) else { return Ok(()) };
 
@@ -1515,15 +1515,7 @@ pub fn main() -> ! {
     let mut callbacks = TimePassesCallbacks::default();
     let using_internal_features = install_ice_hook(DEFAULT_BUG_REPORT_URL, |_| ());
     let exit_code = catch_with_exit_code(|| {
-        let args = env::args_os()
-            .enumerate()
-            .map(|(i, arg)| {
-                arg.into_string().unwrap_or_else(|arg| {
-                    early_dcx.early_fatal(format!("argument {i} is not valid Unicode: {arg:?}"))
-                })
-            })
-            .collect::<Vec<_>>();
-        RunCompiler::new(&args, &mut callbacks)
+        RunCompiler::new(&args::raw_args(&early_dcx)?, &mut callbacks)
             .set_using_internal_features(using_internal_features)
             .run()
     });