Minimize pub usage in source_map.rs.

Most notably, this commit changes the `pub use crate::*;` in that file
to `use crate::*;`. This requires a lot of `use` items in other crates
to be adjusted, because everything defined within `rustc_span::*` was
also available via `rustc_span::source_map::*`, which is bizarre.

The commit also removes `SourceMap::span_to_relative_line_string`, which
is unused.

compiler/rustc_parse/src/parser/expr.rs

@@ -32,10 +32,10 @@ use rustc_macros::Subdiagnostic;
 use rustc_session::errors::{report_lit_error, ExprParenthesesNeeded};
 use rustc_session::lint::builtin::BREAK_WITH_LABEL_AND_LOOP;
 use rustc_session::lint::BuiltinLintDiagnostics;
-use rustc_span::source_map::{self, Span, Spanned};
+use rustc_span::source_map::{self, Spanned};
 use rustc_span::symbol::kw::PathRoot;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
-use rustc_span::{BytePos, Pos};
+use rustc_span::{BytePos, Pos, Span};
 use thin_vec::{thin_vec, ThinVec};
 
 /// Possibly accepts an `token::Interpolated` expression (a pre-parsed expression

compiler/rustc_parse/src/parser/item.rs

@@ -22,9 +22,9 @@ use rustc_errors::{
 };
 use rustc_span::edit_distance::edit_distance;
 use rustc_span::edition::Edition;
-use rustc_span::source_map::{self, Span};
+use rustc_span::source_map;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
-use rustc_span::DUMMY_SP;
+use rustc_span::{Span, DUMMY_SP};
 use std::fmt::Write;
 use std::mem;
 use thin_vec::{thin_vec, ThinVec};

compiler/rustc_parse/src/parser/mod.rs

@@ -36,8 +36,8 @@ use rustc_errors::{
     Applicability, DiagnosticBuilder, ErrorGuaranteed, FatalError, IntoDiagnostic, MultiSpan,
 };
 use rustc_session::parse::ParseSess;
-use rustc_span::source_map::{Span, DUMMY_SP};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
+use rustc_span::{Span, DUMMY_SP};
 use std::ops::Range;
 use std::{mem, slice};
 use thin_vec::ThinVec;

compiler/rustc_parse/src/parser/pat.rs

@@ -20,8 +20,9 @@ use rustc_ast::{
 use rustc_ast_pretty::pprust;
 use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed, IntoDiagnostic, PResult};
 use rustc_session::errors::ExprParenthesesNeeded;
-use rustc_span::source_map::{respan, Span, Spanned};
+use rustc_span::source_map::{respan, Spanned};
 use rustc_span::symbol::{kw, sym, Ident};
+use rustc_span::Span;
 use thin_vec::{thin_vec, ThinVec};
 
 #[derive(PartialEq, Copy, Clone)]

compiler/rustc_parse/src/parser/path.rs

@@ -10,8 +10,8 @@ use rustc_ast::{
     Path, PathSegment, QSelf,
 };
 use rustc_errors::{Applicability, IntoDiagnostic, PResult};
-use rustc_span::source_map::{BytePos, Span};
 use rustc_span::symbol::{kw, sym, Ident};
+use rustc_span::{BytePos, Span};
 use std::mem;
 use thin_vec::ThinVec;
 use tracing::debug;

compiler/rustc_parse/src/parser/stmt.rs

@@ -20,8 +20,8 @@ use rustc_ast::{AttrStyle, AttrVec, LocalKind, MacCall, MacCallStmt, MacStmtStyl
 use rustc_ast::{Block, BlockCheckMode, Expr, ExprKind, HasAttrs, Local, Stmt};
 use rustc_ast::{StmtKind, DUMMY_NODE_ID};
 use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed, PResult};
-use rustc_span::source_map::{BytePos, Span};
 use rustc_span::symbol::{kw, sym, Ident};
+use rustc_span::{BytePos, Span};
 
 use std::borrow::Cow;
 use std::mem;

compiler/rustc_parse/src/parser/ty.rs

@@ -18,9 +18,8 @@ use rustc_ast::{
     TraitObjectSyntax, Ty, TyKind,
 };
 use rustc_errors::{Applicability, PResult};
-use rustc_span::source_map::Span;
 use rustc_span::symbol::{kw, sym, Ident};
-use rustc_span::Symbol;
+use rustc_span::{Span, Symbol};
 use thin_vec::{thin_vec, ThinVec};
 
 /// Any `?`, `!`, or `~const` modifiers that appear at the start of a bound.