rustc_log: remove direct dep on tracing_core

required features reexported from tracing

Author: klensy

Cargo.lock

@@ -4052,7 +4052,6 @@ version = "0.0.0"
 dependencies = [
  "rustc_span",
  "tracing",
- "tracing-core",
  "tracing-subscriber",
  "tracing-tree",
 ]

compiler/rustc_log/Cargo.toml

@@ -6,7 +6,6 @@ edition = "2021"
 [dependencies]
 # tidy-alphabetical-start
 tracing = "0.1.28"
-tracing-core = "0.1.30"
 tracing-subscriber = { version = "0.3.3", default-features = false, features = ["fmt", "env-filter", "smallvec", "parking_lot", "ansi"] }
 tracing-tree = "0.3.1"
 # tidy-alphabetical-end

compiler/rustc_log/src/lib.rs

@@ -41,8 +41,7 @@
 use std::env::{self, VarError};
 use std::fmt::{self, Display};
 use std::io::{self, IsTerminal};
-
-use tracing_core::{Event, Subscriber};
+use tracing::{Event, Subscriber};
 use tracing_subscriber::filter::{Directive, EnvFilter, LevelFilter};
 use tracing_subscriber::fmt::FmtContext;
 use tracing_subscriber::fmt::format::{self, FormatEvent, FormatFields};