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/driver.rs

@@ -178,7 +178,7 @@ pub fn main() {
 
     rustc_driver::init_rustc_env_logger(&handler);
 
-    rustc_driver::install_ice_hook(BUG_REPORT_URL, |handler| {
+    let using_internal_features = rustc_driver::install_ice_hook(BUG_REPORT_URL, |handler| {
         // FIXME: this macro calls unwrap internally but is called in a panicking context!  It's not
         // as simple as moving the call from the hook to main, because `install_ice_hook` doesn't
         // accept a generic closure.
@@ -265,9 +265,11 @@ pub fn main() {
         let clippy_enabled = !cap_lints_allow && (!no_deps || in_primary_package);
         if clippy_enabled {
             args.extend(clippy_args);
-            rustc_driver::RunCompiler::new(&args, &mut ClippyCallbacks { clippy_args_var }).run()
+            rustc_driver::RunCompiler::new(&args, &mut ClippyCallbacks { clippy_args_var })
+                .set_using_internal_features(using_internal_features).run()
         } else {
-            rustc_driver::RunCompiler::new(&args, &mut RustcCallbacks { clippy_args_var }).run()
+            rustc_driver::RunCompiler::new(&args, &mut RustcCallbacks { clippy_args_var })
+                .set_using_internal_features(using_internal_features).run()
         }
     }))
 }