Auto merge of #22133 - servo:extern-crate, r=SimonSapin

Use 2018-edition idioms in crates that use that edition

The first commit is almost entirely mechanical, created by running `cargo fix --edition-idioms` and relevant crates. I undid the change of adding an anonymous lifetime parameter in types that have implicit lifetimes parameters, for example replacing `&mut Formatter` with `&mut Formatter<'_>`, because I don’t like it. The remaining changes are, in many places:

* Add `dyn` to trait object types, for example `Rc<gl::Gl>` to `Rc<dyn gl::Gl>`. This change also works in the 2015 edition.
* Remove `extern crate` where is it made unneeded by changes to the import/module system.

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1 files changed, 2 insertions, 2 deletions

diff --git a/components/script/dom/webgl_extensions/wrapper.rs b/components/script/dom/webgl_extensions/wrapper.rs
index 9918952dc73..11c9bac3d7e 100644
--- a/components/script/dom/webgl_extensions/wrapper.rs
+++ b/components/script/dom/webgl_extensions/wrapper.rs
@@ -25,7 +25,7 @@ pub trait WebGLExtensionWrapper: JSTraceable + MallocSizeOf {
     fn is_enabled(&self) -> bool;
     fn enable(&self, ext: &WebGLExtensions);
     fn name(&self) -> &'static str;
-    fn as_any(&self) -> &Any;
+    fn as_any(&self) -> &dyn Any;
 }
 
 #[must_root]
@@ -85,7 +85,7 @@ where
         T::name()
     }
 
-    fn as_any<'a>(&'a self) -> &'a Any {
+    fn as_any<'a>(&'a self) -> &'a dyn Any {
         self
     }
 }