Remove extern crate tracing from numerous crates.

compiler/rustc_errors/src/diagnostic.rs

@@ -18,6 +18,7 @@ use std::marker::PhantomData;
 use std::ops::{Deref, DerefMut};
 use std::panic;
 use std::thread::panicking;
+use tracing::debug;
 
 /// Error type for `DiagInner`'s `suggestions` field, indicating that
 /// `.disable_suggestions()` was called on the `DiagInner`.

compiler/rustc_errors/src/emitter.rs

@@ -35,6 +35,7 @@ use std::iter;
 use std::path::Path;
 use termcolor::{Buffer, BufferWriter, ColorChoice, ColorSpec, StandardStream};
 use termcolor::{Color, WriteColor};
+use tracing::{debug, instrument, trace, warn};
 
 /// Default column width, used in tests and when terminal dimensions cannot be determined.
 const DEFAULT_COLUMN_WIDTH: usize = 140;

compiler/rustc_errors/src/lib.rs

@@ -25,9 +25,6 @@
 #![feature(yeet_expr)]
 // tidy-alphabetical-end
 
-#[macro_use]
-extern crate tracing;
-
 extern crate self as rustc_errors;
 
 pub use codes::*;
@@ -74,6 +71,7 @@ use std::num::NonZero;
 use std::ops::DerefMut;
 use std::panic;
 use std::path::{Path, PathBuf};
+use tracing::debug;
 
 use Level::*;
 

compiler/rustc_errors/src/translation.rs

@@ -6,6 +6,7 @@ pub use rustc_error_messages::FluentArgs;
 use std::borrow::Cow;
 use std::env;
 use std::error::Report;
+use tracing::{debug, trace};
 
 /// Convert diagnostic arguments (a rustc internal type that exists to implement
 /// `Encodable`/`Decodable`) into `FluentArgs` which is necessary to perform translation.