Pass args after -- to subcommands

Author: clubby789

src/bootstrap/config.rs

@@ -867,6 +867,7 @@ impl Config {
 
         // Set flags.
         config.paths = std::mem::take(&mut flags.paths);
+        config.free_args = std::mem::take(&mut flags.free_args);
         config.exclude = flags.exclude.into_iter().map(|path| TaskPath::parse(path)).collect();
         config.include_default_paths = flags.include_default_paths;
         config.rustc_error_format = flags.error_format;
@@ -879,7 +880,6 @@ impl Config {
         config.keep_stage = flags.keep_stage;
         config.keep_stage_std = flags.keep_stage_std;
         config.color = flags.color;
-        config.free_args = flags.free_args.clone().unwrap_or_default();
         if matches!(flags.deny_warnings, crate::flags::Warnings::Deny) {
             config.deny_warnings = true;
         }

src/bootstrap/flags.rs

@@ -149,6 +149,9 @@ pub struct Flags {
     #[arg(global(true))]
     /// paths for the subcommand
     pub paths: Vec<PathBuf>,
+    /// arguments passed to subcommands
+    #[arg(global(true), last(true), value_name = "ARGS")]
+    pub free_args: Vec<String>,
 }
 
 impl Flags {

src/bootstrap/run.rs

@@ -184,7 +184,6 @@ impl Step for Miri {
         miri.arg("--").arg("--target").arg(target.rustc_target_arg());
         miri.args(builder.config.cmd.args());
         miri.args(&builder.config.free_args);
-
         // miri tests need to know about the stage sysroot
         miri.env("MIRI_SYSROOT", &miri_sysroot);