Stop telling people to submit bugs for internal feature ICEs

This keeps track of usage of internal features, and changes the message
to instead tell them that using internal features is not supported.

See MCP 620.

Author: Noratrieb

src/bin/miri.rs

@@ -241,6 +241,7 @@ fn run_compiler(
     mut args: Vec<String>,
     target_crate: bool,
     callbacks: &mut (dyn rustc_driver::Callbacks + Send),
+    using_internal_features: std::sync::Arc<std::sync::atomic::AtomicBool>
 ) -> ! {
     if target_crate {
         // Miri needs a custom sysroot for target crates.
@@ -273,7 +274,8 @@ fn run_compiler(
 
     // Invoke compiler, and handle return code.
     let exit_code = rustc_driver::catch_with_exit_code(move || {
-        rustc_driver::RunCompiler::new(&args, callbacks).run()
+        rustc_driver::RunCompiler::new(&args, callbacks)
+            .set_using_internal_features(using_internal_features).run()
     });
     std::process::exit(exit_code)
 }
@@ -295,7 +297,7 @@ fn main() {
     // If the environment asks us to actually be rustc, then do that.
     if let Some(crate_kind) = env::var_os("MIRI_BE_RUSTC") {
         // Earliest rustc setup.
-        rustc_driver::install_ice_hook(rustc_driver::DEFAULT_BUG_REPORT_URL, |_| ());
+        let using_internal_features = rustc_driver::install_ice_hook(rustc_driver::DEFAULT_BUG_REPORT_URL, |_| ());
         rustc_driver::init_rustc_env_logger(&handler);
 
         let target_crate = if crate_kind == "target" {
@@ -311,11 +313,12 @@ fn main() {
             env::args().collect(),
             target_crate,
             &mut MiriBeRustCompilerCalls { target_crate },
+            using_internal_features,
         )
     }
 
     // Add an ICE bug report hook.
-    rustc_driver::install_ice_hook("https://github.com/rust-lang/miri/issues/new", |_| ());
+    let using_internal_features = rustc_driver::install_ice_hook("https://github.com/rust-lang/miri/issues/new", |_| ());
 
     // Init loggers the Miri way.
     init_early_loggers(&handler);
@@ -578,5 +581,5 @@ fn main() {
 
     debug!("rustc arguments: {:?}", rustc_args);
     debug!("crate arguments: {:?}", miri_config.args);
-    run_compiler(rustc_args, /* target_crate: */ true, &mut MiriCompilerCalls { miri_config })
+    run_compiler(rustc_args, /* target_crate: */ true, &mut MiriCompilerCalls { miri_config }, using_internal_features)
 }