Auto merge of #101239 - oli-obk:tracing_cleanup, r=estebank

Tracing cleanup

r? `@ghost`

Author: bors

compiler/rustc_ast/src/lib.rs

@@ -26,6 +26,9 @@
 #[macro_use]
 extern crate rustc_macros;
 
+#[macro_use]
+extern crate tracing;
+
 pub mod util {
     pub mod classify;
     pub mod comments;

compiler/rustc_ast/src/util/literal.rs

@@ -9,7 +9,6 @@ use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
 
 use std::ascii;
-use tracing::debug;
 
 pub enum LitError {
     NotLiteral,