Remove extern crate tracing from numerous crates.

compiler/rustc_hir/src/definitions.rs

@@ -7,15 +7,14 @@
 pub use crate::def_id::DefPathHash;
 use crate::def_id::{CrateNum, DefIndex, LocalDefId, StableCrateId, CRATE_DEF_INDEX, LOCAL_CRATE};
 use crate::def_path_hash_map::DefPathHashMap;
-
 use rustc_data_structures::stable_hasher::{Hash64, StableHasher};
 use rustc_data_structures::unord::UnordMap;
 use rustc_index::IndexVec;
 use rustc_macros::{Decodable, Encodable};
 use rustc_span::symbol::{kw, sym, Symbol};
-
 use std::fmt::{self, Write};
 use std::hash::Hash;
+use tracing::{debug, instrument};
 
 /// The `DefPathTable` maps `DefIndex`es to `DefKey`s and vice versa.
 /// Internally the `DefPathTable` holds a tree of `DefKey`s, where each `DefKey`

compiler/rustc_hir/src/hir.rs

@@ -3,7 +3,6 @@ use crate::def_id::{DefId, LocalDefIdMap};
 pub(crate) use crate::hir_id::{HirId, ItemLocalId, ItemLocalMap, OwnerId};
 use crate::intravisit::FnKind;
 use crate::LangItem;
-
 use rustc_ast as ast;
 use rustc_ast::util::parser::ExprPrecedence;
 use rustc_ast::{Attribute, FloatTy, IntTy, Label, LitKind, TraitObjectSyntax, UintTy};
@@ -21,9 +20,9 @@ use rustc_span::ErrorGuaranteed;
 use rustc_span::{def_id::LocalDefId, BytePos, Span, DUMMY_SP};
 use rustc_target::asm::InlineAsmRegOrRegClass;
 use rustc_target::spec::abi::Abi;
-
 use smallvec::SmallVec;
 use std::fmt;
+use tracing::debug;
 
 #[derive(Debug, Copy, Clone, HashStable_Generic)]
 pub struct Lifetime {

compiler/rustc_hir/src/lib.rs

@@ -10,9 +10,6 @@
 #![feature(variant_count)]
 #![allow(internal_features)]
 
-#[macro_use]
-extern crate tracing;
-
 extern crate self as rustc_hir;
 
 mod arena;