Remove #[macro_use] extern crate tracing from rustc_parse.

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -45,6 +45,7 @@ use rustc_span::{BytePos, Span, SpanSnippetError, Symbol, DUMMY_SP};
 use std::mem::take;
 use std::ops::{Deref, DerefMut};
 use thin_vec::{thin_vec, ThinVec};
+use tracing::{debug, trace};
 
 /// Creates a placeholder argument.
 pub(super) fn dummy_arg(ident: Ident, guar: ErrorGuaranteed) -> Param {

compiler/rustc_parse/src/parser/expr.rs

@@ -36,6 +36,7 @@ use rustc_span::source_map::{self, Spanned};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{BytePos, ErrorGuaranteed, Pos, Span};
 use thin_vec::{thin_vec, ThinVec};
+use tracing::instrument;
 
 /// Possibly accepts an `token::Interpolated` expression (a pre-parsed expression
 /// dropped into the token stream, which happens while parsing the result of

compiler/rustc_parse/src/parser/item.rs

@@ -23,6 +23,7 @@ use rustc_span::{Span, DUMMY_SP};
 use std::fmt::Write;
 use std::mem;
 use thin_vec::{thin_vec, ThinVec};
+use tracing::debug;
 
 impl<'a> Parser<'a> {
     /// Parses a source module as a crate. This is the main entry point for the parser.