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 to `rustc_span::`.
This is a 300+ net line of code reduction, mostly because many files
with two `use rustc_span` items can be reduced to one.

Author: nnethercote

compiler/rustc_abi/src/extern_abi/mod.rs

@@ -1,8 +1,7 @@
 use std::fmt;
 
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
-use rustc_span::symbol::sym;
-use rustc_span::{Span, Symbol};
+use rustc_span::{Span, Symbol, sym};
 
 #[cfg(test)]
 mod tests;

compiler/rustc_ast/src/ast.rs

@@ -31,8 +31,7 @@ use rustc_data_structures::sync::Lrc;
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
 pub use rustc_span::AttrId;
 use rustc_span::source_map::{Spanned, respan};
-use rustc_span::symbol::{Ident, Symbol, kw, sym};
-use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span};
+use rustc_span::{DUMMY_SP, ErrorGuaranteed, Ident, Span, Symbol, kw, sym};
 use thin_vec::{ThinVec, thin_vec};
 
 pub use crate::format::*;

compiler/rustc_ast/src/attr/mod.rs

@@ -4,8 +4,7 @@ use std::iter;
 use std::sync::atomic::{AtomicU32, Ordering};
 
 use rustc_index::bit_set::GrowableBitSet;
-use rustc_span::Span;
-use rustc_span::symbol::{Ident, Symbol, sym};
+use rustc_span::{Ident, Span, Symbol, sym};
 use smallvec::{SmallVec, smallvec};
 use thin_vec::{ThinVec, thin_vec};
 

compiler/rustc_ast/src/entry.rs

@@ -1,5 +1,4 @@
-use rustc_span::Symbol;
-use rustc_span::symbol::sym;
+use rustc_span::{Symbol, sym};
 
 use crate::{Attribute, attr};
 

compiler/rustc_ast/src/expand/allocator.rs

@@ -1,5 +1,5 @@
 use rustc_macros::HashStable_Generic;
-use rustc_span::symbol::{Symbol, sym};
+use rustc_span::{Symbol, sym};
 
 #[derive(Clone, Debug, Copy, Eq, PartialEq, HashStable_Generic)]
 pub enum AllocatorKind {

compiler/rustc_ast/src/expand/mod.rs

@@ -1,8 +1,8 @@
 //! Definitions shared by macros / syntax extensions and e.g. `rustc_middle`.
 
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
+use rustc_span::Ident;
 use rustc_span::def_id::DefId;
-use rustc_span::symbol::Ident;
 
 use crate::MetaItem;
 

compiler/rustc_ast/src/format.rs

@@ -1,7 +1,6 @@
 use rustc_data_structures::fx::FxHashMap;
 use rustc_macros::{Decodable, Encodable};
-use rustc_span::Span;
-use rustc_span::symbol::{Ident, Symbol};
+use rustc_span::{Ident, Span, Symbol};
 
 use crate::Expr;
 use crate::ptr::P;

compiler/rustc_ast/src/mut_visit.rs

@@ -13,9 +13,8 @@ use std::panic;
 use rustc_data_structures::flat_map_in_place::FlatMapInPlace;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_data_structures::sync::Lrc;
-use rustc_span::Span;
 use rustc_span::source_map::Spanned;
-use rustc_span::symbol::Ident;
+use rustc_span::{Ident, Span};
 use smallvec::{Array, SmallVec, smallvec};
 use thin_vec::ThinVec;
 

compiler/rustc_ast/src/token.rs

@@ -11,11 +11,10 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::Lrc;
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
 use rustc_span::edition::Edition;
+use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, kw, sym};
 #[allow(clippy::useless_attribute)] // FIXME: following use of `hidden_glob_reexports` incorrectly triggers `useless_attribute` lint.
 #[allow(hidden_glob_reexports)]
-use rustc_span::symbol::{Ident, Symbol};
-use rustc_span::symbol::{kw, sym};
-use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span};
+use rustc_span::{Ident, Symbol};
 
 use crate::ast;
 use crate::ptr::P;

compiler/rustc_ast/src/util/literal.rs

@@ -5,8 +5,7 @@ use std::{ascii, fmt, str};
 use rustc_lexer::unescape::{
     MixedUnit, Mode, byte_from_char, unescape_byte, unescape_char, unescape_mixed, unescape_unicode,
 };
-use rustc_span::Span;
-use rustc_span::symbol::{Symbol, kw, sym};
+use rustc_span::{Span, Symbol, kw, sym};
 use tracing::debug;
 
 use crate::ast::{self, LitKind, MetaItemLit, StrStyle};