Replace script_plugins with a clippy like rustc driver (named crown) (#30508)

* Remove script_plugins

* Use crown instead of script_plugins

* crown_is_not_used

* Use crown in command base

* bootstrap crown

* tidy happy

* disable sccache

* Bring crown in tree

* Install crown from tree

* fix windows ci

* fix warning

* fix mac

libscript_plugins.dylib is not available anymore

* Update components/script/lib.rs

Co-authored-by: Martin Robinson <mrobinson@igalia.com>

* Update for nightly-2023-03-18

Mostly just based off https://github.com/servo/servo/pull/30630

* Always install crown

it's slow only when there is new version

* Run crown test with `mach test-unit`

* Small fixups; better trace_in_no_trace tests

* Better doc

* crown in config.toml

* Fix tidy for real

* no sccache on rustc_wrapper

* document rustc overrides

* fixup of compiletest

* Make a few minor comment adjustments

* Fix a typo in python/servo/platform/base.py

Co-authored-by: Samson <16504129+sagudev@users.noreply.github.com>

* Proper test types

* Ignore tidy on crown/tests

---------

Co-authored-by: Martin Robinson <mrobinson@igalia.com>

support/crown/tests/run-pass/trace_in_no_trace_composable.rs

@@ -0,0 +1,24 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+/// Mock `JSTraceable`
+pub trait JSTraceable {}
+
+struct TraceableStruct;
+impl JSTraceable for TraceableStruct {}
+
+struct NotTraceableStruct;
+
+// `must_not_have_traceable(1)` indicates that the second generic argument should
+// not be traceable and this test verifies that this lint passes.
+#[crown::trace_in_no_trace_lint::must_not_have_traceable(1)]
+struct NoTraceComposable<Traceable, NoTraceable> {
+    t: Traceable,
+    n: NoTraceable,
+}
+
+// this is ok: TraceableStruct is traceable
+struct Foo(NoTraceComposable<TraceableStruct, NotTraceableStruct>);
+
+fn main() {}

support/crown/tests/run-pass/trace_in_no_trace_ok.rs

@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+/// Mock `JSTraceable`
+pub trait JSTraceable {}
+
+struct TraceableStruct;
+impl JSTraceable for TraceableStruct {}
+
+struct NotTraceableStruct;
+
+#[crown::trace_in_no_trace_lint::must_not_have_traceable]
+struct NoTrace<T>(T);
+
+struct Foo(NoTrace<NotTraceableStruct>);
+
+fn main() {}

support/crown/tests/run-pass/unrooted_must_root_ok.rs

@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+// compile-flags: --error-format=human
+#[crown::unrooted_must_root_lint::must_root]
+struct Foo(i32);
+#[crown::unrooted_must_root_lint::must_root]
+struct Bar(Foo);
+
+fn foo1(_: &Foo) {}
+fn foo2(_: &()) -> &Foo {
+    unimplemented!()
+}
+
+fn main() {}