Replace compiletest suite by doc-tests with compile_fail

compiletest-rs use internal rustc APIs and is broken in today’s Nightly.
rustdoc however is maintained with rustc and so much less fragile.

tests/unit/malloc_size_of/lib.rs

@@ -0,0 +1,109 @@
+/* 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 http://mozilla.org/MPL/2.0/. */
+
+/**
+```
+extern crate malloc_size_of;
+extern crate servo_arc;
+
+fn sizeable<T: malloc_size_of::MallocSizeOf>() {}
+fn shallow_sizeable<T: malloc_size_of::MallocShallowSizeOf>() {}
+fn cloneable<T: Clone>() {}
+
+fn main() {
+    cloneable::<servo_arc::Arc<i32>>();
+    cloneable::<std::sync::Arc<i32>>();
+    cloneable::<std::rc::Rc<i32>>();
+}
+```
+*/
+pub fn imports_ok() {}
+
+pub mod does_not_impl_malloc_size_of {
+    /**
+    ```compile_fail,E0277
+    extern crate malloc_size_of;
+    extern crate servo_arc;
+
+    fn sizeable<T: malloc_size_of::MallocSizeOf>() {}
+
+    fn main() {
+        sizeable::<servo_arc::Arc<i32>>();
+    }
+    ```
+    */
+    pub fn servo_arc() {}
+
+
+    /**
+    ```compile_fail,E0277
+    extern crate malloc_size_of;
+
+    fn sizeable<T: malloc_size_of::MallocSizeOf>() {}
+
+    fn main() {
+        sizeable::<std::sync::Arc<i32>>();
+    }
+    ```
+    */
+    pub fn std_arc() {}
+
+
+    /**
+    ```compile_fail,E0277
+    extern crate malloc_size_of;
+
+    fn sizeable<T: malloc_size_of::MallocSizeOf>() {}
+
+    fn main() {
+        sizeable::<std::rc::Rc<i32>>();
+    }
+    ```
+    */
+    pub fn rc() {}
+}
+
+pub mod does_not_impl_malloc_shallow_size_of {
+    /**
+    ```compile_fail,E0277
+    extern crate malloc_size_of;
+    extern crate servo_arc;
+
+    fn shallow_sizeable<T: malloc_size_of::MallocShallowSizeOf>() {}
+
+    fn main() {
+        shallow_sizeable::<servo_arc::Arc<i32>>();
+    }
+    ```
+    */
+    pub fn servo_arc() {}
+
+
+    /**
+    ```compile_fail,E0277
+    extern crate malloc_size_of;
+
+    fn shallow_sizeable<T: malloc_size_of::MallocShallowSizeOf>() {}
+
+    fn main() {
+        shallow_sizeable::<std::sync::Arc<i32>>();
+    }
+    ```
+    */
+    pub fn std_arc() {}
+
+
+    /**
+    ```compile_fail,E0277
+    extern crate malloc_size_of;
+
+    fn shallow_sizeable<T: malloc_size_of::MallocShallowSizeOf>() {}
+
+    fn main() {
+        shallow_sizeable::<std::rc::Rc<i32>>();
+    }
+    ```
+    */
+    pub fn rc() {}
+}