Re-export more `rustc_span::symbol` things from `rustc_span`.

`rustc_span::symbol` defines some things that are re-exported from
`rustc_span`, such as `Symbol` and `sym`. But it doesn't re-export some
closely related things such as `Ident` and `kw`. So you can do `use
rustc_span::{Symbol, sym}` but you have to do `use
rustc_span::symbol::{Ident, kw}`, which is inconsistent for no good
reason.

This commit re-exports `Ident`, `kw`, and `MacroRulesNormalizedIdent`,
and changes many `rustc_span::symbol::` qualifiers in `compiler/` to
`rustc_span::`. This is a 200+ net line of code reduction, mostly
because many files with two `use rustc_span` items can be reduced to
one.

1 files changed, 2 insertions, 2 deletions

diff --git a/compiler/rustc_middle/src/lint.rs b/compiler/rustc_middle/src/lint.rs
index 971d036fa69..620d9f1c357 100644
--- a/compiler/rustc_middle/src/lint.rs
+++ b/compiler/rustc_middle/src/lint.rs
@@ -9,7 +9,7 @@ use rustc_session::Session;
 use rustc_session::lint::builtin::{self, FORBIDDEN_LINT_GROUPS};
 use rustc_session::lint::{FutureIncompatibilityReason, Level, Lint, LintExpectationId, LintId};
 use rustc_span::hygiene::{ExpnKind, MacroKind};
-use rustc_span::{DUMMY_SP, DesugaringKind, Span, Symbol, symbol};
+use rustc_span::{DUMMY_SP, DesugaringKind, Span, Symbol, kw};
 use tracing::instrument;
 
 use crate::ty::TyCtxt;
@@ -37,7 +37,7 @@ pub enum LintLevelSource {
 impl LintLevelSource {
     pub fn name(&self) -> Symbol {
         match *self {
-            LintLevelSource::Default => symbol::kw::Default,
+            LintLevelSource::Default => kw::Default,
             LintLevelSource::Node { name, .. } => name,
             LintLevelSource::CommandLine(name, _) => name,
         }