remove redundant imports

detects redundant imports that can be eliminated.

for #117772 :

In order to facilitate review and modification, split the checking code and
removing redundant imports code into two PR.

clippy_lints/src/escape.rs

@@ -1,5 +1,5 @@
 use clippy_utils::diagnostics::span_lint_hir;
-use rustc_hir::{self, intravisit, AssocItemKind, Body, FnDecl, HirId, HirIdSet, Impl, ItemKind, Node, Pat, PatKind};
+use rustc_hir::{intravisit, AssocItemKind, Body, FnDecl, HirId, HirIdSet, Impl, ItemKind, Node, Pat, PatKind};
 use rustc_hir_typeck::expr_use_visitor::{Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass};

clippy_lints/src/loops/manual_memcpy.rs

@@ -12,7 +12,6 @@ use rustc_lint::LateContext;
 use rustc_middle::ty::{self, Ty};
 use rustc_span::symbol::sym;
 use std::fmt::Display;
-use std::iter::Iterator;
 
 /// Checks for `for` loops that sequentially copy items from one slice-like
 /// object to another.

clippy_lints/src/loops/needless_range_loop.rs

@@ -13,7 +13,7 @@ use rustc_lint::LateContext;
 use rustc_middle::middle::region;
 use rustc_middle::ty::{self, Ty};
 use rustc_span::symbol::{sym, Symbol};
-use std::iter::{self, Iterator};
+use std::iter::{self};
 use std::mem;
 
 /// Checks for looping over a range and then indexing a sequence with it.

clippy_lints/src/loops/never_loop.rs

@@ -8,7 +8,7 @@ use rustc_errors::Applicability;
 use rustc_hir::{Block, Destination, Expr, ExprKind, HirId, InlineAsmOperand, Pat, Stmt, StmtKind};
 use rustc_lint::LateContext;
 use rustc_span::{sym, Span};
-use std::iter::{once, Iterator};
+use std::iter::once;
 
 pub(super) fn check<'tcx>(
     cx: &LateContext<'tcx>,

clippy_lints/src/loops/same_item_push.rs

@@ -11,7 +11,6 @@ use rustc_hir::{BindingAnnotation, Block, Expr, ExprKind, HirId, Mutability, Nod
 use rustc_lint::LateContext;
 use rustc_span::symbol::sym;
 use rustc_span::SyntaxContext;
-use std::iter::Iterator;
 
 /// Detects for loop pushing the same item into a Vec
 pub(super) fn check<'tcx>(

clippy_lints/src/loops/utils.rs

@@ -9,7 +9,6 @@ use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::{self, Ty};
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{sym, Symbol};
-use std::iter::Iterator;
 
 #[derive(Debug, PartialEq, Eq)]
 enum IncrementVisitorVarState {

clippy_lints/src/methods/option_map_unwrap_or.rs

@@ -6,7 +6,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
 use rustc_hir::def::Res;
 use rustc_hir::intravisit::{walk_path, Visitor};
-use rustc_hir::{self, ExprKind, HirId, Node, PatKind, Path, QPath};
+use rustc_hir::{ExprKind, HirId, Node, PatKind, Path, QPath};
 use rustc_lint::LateContext;
 use rustc_middle::hir::nested_filter;
 use rustc_span::{sym, Span};

clippy_lints/src/missing_inline.rs

@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::span_lint;
 use rustc_ast::ast;
 use rustc_hir as hir;
-use rustc_lint::{self, LateContext, LateLintPass, LintContext};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_session::declare_lint_pass;
 use rustc_span::{sym, Span};