Remove #[macro_use] extern crate tracing from rustc_hir_analysis.

compiler/rustc_hir_analysis/src/variance/constraints.rs

@@ -8,6 +8,7 @@ use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_middle::ty::{self, GenericArgKind, GenericArgsRef, Ty, TyCtxt};
 use rustc_middle::{bug, span_bug};
+use tracing::{debug, instrument};
 
 use super::terms::VarianceTerm::*;
 use super::terms::*;

compiler/rustc_hir_analysis/src/variance/mod.rs

@@ -12,6 +12,7 @@ use rustc_middle::span_bug;
 use rustc_middle::ty::{
     self, CrateVariancesMap, GenericArgsRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable,
 };
+use tracing::{debug, instrument};
 
 /// Defines the `TermsContext` basically houses an arena where we can
 /// allocate terms.

compiler/rustc_hir_analysis/src/variance/solve.rs

@@ -7,6 +7,7 @@
 
 use rustc_hir::def_id::DefIdMap;
 use rustc_middle::ty;
+use tracing::debug;
 
 use super::constraints::*;
 use super::terms::VarianceTerm::*;

compiler/rustc_hir_analysis/src/variance/terms.rs

@@ -15,6 +15,7 @@ use rustc_arena::DroplessArena;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{LocalDefId, LocalDefIdMap};
 use rustc_middle::ty::{self, TyCtxt};
+use tracing::debug;
 
 use self::VarianceTerm::*;