Remove extern crate tracing from numerous crates.

compiler/rustc_session/src/config.rs

@@ -33,6 +33,7 @@ use std::iter;
 use std::path::{Path, PathBuf};
 use std::str::{self, FromStr};
 use std::sync::LazyLock;
+use tracing::debug;
 
 mod cfg;
 pub mod sigpipe;

compiler/rustc_session/src/filesearch.rs

@@ -1,13 +1,12 @@
 //! A module for searching for libraries
 
-use rustc_fs_util::try_canonicalize;
+use crate::search_paths::{PathKind, SearchPath};
+use rustc_fs_util::{fix_windows_verbatim_for_gcc, try_canonicalize};
 use smallvec::{smallvec, SmallVec};
 use std::env;
 use std::fs;
 use std::path::{Path, PathBuf};
-
-use crate::search_paths::{PathKind, SearchPath};
-use rustc_fs_util::fix_windows_verbatim_for_gcc;
+use tracing::debug;
 
 #[derive(Clone)]
 pub struct FileSearch<'a> {

compiler/rustc_session/src/lib.rs

@@ -8,9 +8,6 @@
 
 pub mod errors;
 
-#[macro_use]
-extern crate tracing;
-
 pub mod utils;
 pub use lint::{declare_lint, declare_lint_pass, declare_tool_lint, impl_lint_pass};
 pub use rustc_lint_defs as lint;