Remove some low-value use renamings.

There are a few common abbreviations like `use rustc_ast as ast` and
`use rust_hir as hir` for names that are used a lot. But there are also
some cases where a crate is renamed just once in the whole codebase, and
that ends up making things harder to read rather than easier. This
commit removes them.

Author: nnethercote

compiler/rustc_errors/src/diagnostic_impls.rs

@@ -13,7 +13,7 @@ use rustc_span::symbol::{Ident, MacroRulesNormalizedIdent, Symbol};
 use rustc_span::Span;
 use rustc_target::abi::TargetDataLayoutErrors;
 use rustc_target::spec::{PanicStrategy, SplitDebuginfo, StackProtector, TargetTriple};
-use rustc_type_ir as type_ir;
+use rustc_type_ir::{ClosureKind, FloatTy};
 use std::backtrace::Backtrace;
 use std::borrow::Cow;
 use std::fmt;
@@ -196,7 +196,7 @@ impl IntoDiagArg for ast::token::TokenKind {
     }
 }
 
-impl IntoDiagArg for type_ir::FloatTy {
+impl IntoDiagArg for FloatTy {
     fn into_diag_arg(self) -> DiagArgValue {
         DiagArgValue::Str(Cow::Borrowed(self.name_str()))
     }
@@ -252,7 +252,7 @@ impl IntoDiagArg for Level {
     }
 }
 
-impl IntoDiagArg for type_ir::ClosureKind {
+impl IntoDiagArg for ClosureKind {
     fn into_diag_arg(self) -> DiagArgValue {
         DiagArgValue::Str(self.as_str().into())
     }

compiler/rustc_hir_typeck/src/pat.rs

@@ -10,7 +10,6 @@ use rustc_hir::pat_util::EnumerateAndAdjustIterator;
 use rustc_hir::{self as hir, BindingMode, ByRef, HirId, Mutability, Pat, PatKind};
 use rustc_infer::infer;
 use rustc_infer::infer::type_variable::TypeVariableOrigin;
-use rustc_lint as lint;
 use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::ty::{self, Ty, TypeVisitableExt};
 use rustc_session::lint::builtin::NON_EXHAUSTIVE_OMITTED_PATTERNS;
@@ -684,7 +683,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             {
                 // `mut x` resets the binding mode in edition <= 2021.
                 self.tcx.emit_node_span_lint(
-                    lint::builtin::DEREFERENCING_MUT_BINDING,
+                    rustc_lint::builtin::DEREFERENCING_MUT_BINDING,
                     pat.hir_id,
                     pat.span,
                     errors::DereferencingMutBinding { span: pat.span },

compiler/rustc_interface/src/passes.rs

@@ -4,7 +4,6 @@ use crate::proc_macro_decls;
 use crate::util;
 
 use rustc_ast::{self as ast, visit};
-use rustc_borrowck as mir_borrowck;
 use rustc_codegen_ssa::traits::CodegenBackend;
 use rustc_data_structures::parallel;
 use rustc_data_structures::steal::Steal;
@@ -20,7 +19,6 @@ use rustc_middle::arena::Arena;
 use rustc_middle::dep_graph::DepGraph;
 use rustc_middle::ty::{self, GlobalCtxt, RegisteredTools, TyCtxt};
 use rustc_middle::util::Providers;
-use rustc_mir_build as mir_build;
 use rustc_parse::{parse_crate_from_file, parse_crate_from_source_str, validate_attr};
 use rustc_passes::{abi_test, hir_stats, layout_test};
 use rustc_resolve::Resolver;
@@ -616,8 +614,8 @@ pub static DEFAULT_QUERY_PROVIDERS: LazyLock<Providers> = LazyLock::new(|| {
     proc_macro_decls::provide(providers);
     rustc_const_eval::provide(providers);
     rustc_middle::hir::provide(providers);
-    mir_borrowck::provide(providers);
-    mir_build::provide(providers);
+    rustc_borrowck::provide(providers);
+    rustc_mir_build::provide(providers);
     rustc_mir_transform::provide(providers);
     rustc_monomorphize::provide(providers);
     rustc_privacy::provide(providers);

compiler/rustc_interface/src/util.rs

@@ -7,18 +7,16 @@ use rustc_data_structures::sync;
 use rustc_metadata::{load_symbol_from_dylib, DylibError};
 use rustc_middle::ty::CurrentGcx;
 use rustc_parse::validate_attr;
-use rustc_session as session;
-use rustc_session::config::{Cfg, OutFileName, OutputFilenames, OutputTypes};
+use rustc_session::config::{host_triple, Cfg, OutFileName, OutputFilenames, OutputTypes};
 use rustc_session::filesearch::sysroot_candidates;
 use rustc_session::lint::{self, BuiltinLintDiag, LintBuffer};
-use rustc_session::{filesearch, Session};
+use rustc_session::output::{categorize_crate_type, CRATE_TYPES};
+use rustc_session::{filesearch, EarlyDiagCtxt, Session};
 use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::edition::Edition;
 use rustc_span::source_map::SourceMapInputs;
 use rustc_span::symbol::sym;
 use rustc_target::spec::Target;
-use session::output::{categorize_crate_type, CRATE_TYPES};
-use session::EarlyDiagCtxt;
 use std::env::consts::{DLL_PREFIX, DLL_SUFFIX};
 use std::path::{Path, PathBuf};
 use std::sync::atomic::{AtomicBool, Ordering};
@@ -286,7 +284,7 @@ fn get_codegen_sysroot(
         "cannot load the default codegen backend twice"
     );
 
-    let target = session::config::host_triple();
+    let target = host_triple();
     let sysroot_candidates = sysroot_candidates();
 
     let sysroot = iter::once(sysroot)