Fix similar_names warnings

Most of these are just `#![allow]`ed, because they are things like using
l vs r to differentiate left vs right. These would be made less clear by
taking the advice of `similar_names`

clippy_lints/src/double_comparison.rs

@@ -49,6 +49,7 @@ impl LintPass for DoubleComparisonPass {
 }
 
 impl<'a, 'tcx> DoubleComparisonPass {
+    #[allow(clippy::similar_names)]
     fn check_binop(
         &self,
         cx: &LateContext<'a, 'tcx>,

clippy_lints/src/enum_clike.rs

@@ -63,16 +63,16 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnportableVariant {
                 let variant = &var.node;
                 if let Some(ref anon_const) = variant.disr_expr {
                     let param_env = ty::ParamEnv::empty();
-                    let did = cx.tcx.hir.body_owner_def_id(anon_const.body);
-                    let substs = Substs::identity_for_item(cx.tcx.global_tcx(), did);
-                    let instance = ty::Instance::new(did, substs);
-                    let cid = GlobalId {
+                    let def_id = cx.tcx.hir.body_owner_def_id(anon_const.body);
+                    let substs = Substs::identity_for_item(cx.tcx.global_tcx(), def_id);
+                    let instance = ty::Instance::new(def_id, substs);
+                    let c_id = GlobalId {
                         instance,
                         promoted: None
                     };
-                    let constant = cx.tcx.const_eval(param_env.and(cid)).ok();
+                    let constant = cx.tcx.const_eval(param_env.and(c_id)).ok();
                     if let Some(Constant::Int(val)) = constant.and_then(|c| miri_to_const(cx.tcx, c)) {
-                        let mut ty = cx.tcx.type_of(did);
+                        let mut ty = cx.tcx.type_of(def_id);
                         if let ty::Adt(adt, _) = ty.sty {
                             if adt.is_enum() {
                                 ty = adt.repr.discr_type().to_ty(cx.tcx);

clippy_lints/src/enum_variants.rs

@@ -255,6 +255,7 @@ impl EarlyLintPass for EnumVariantNames {
         assert!(last.is_some());
     }
 
+    #[allow(clippy::similar_names)]
     fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
         let item_name = item.ident.as_str();
         let item_name_chars = item_name.chars().count();

clippy_lints/src/eq_op.rs

@@ -63,6 +63,7 @@ impl LintPass for EqOp {
 }
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for EqOp {
+    #[allow(clippy::similar_names)]
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
         if let ExprKind::Binary(op, ref left, ref right) = e.node {
             if in_macro(e.span) {

clippy_lints/src/if_let_redundant_pattern_matching.rs

@@ -56,6 +56,7 @@ impl LintPass for Pass {
 }
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
+    #[allow(clippy::similar_names)]
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
         if let ExprKind::Match(ref op, ref arms, MatchSource::IfLetDesugar { .. }) = expr.node {
             if arms[0].pats.len() == 1 {

clippy_lints/src/transmute.rs

@@ -227,6 +227,7 @@ impl LintPass for Transmute {
 }
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute {
+    #[allow(clippy::similar_names)]
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
         if let ExprKind::Call(ref path_expr, ref args) = e.node {
             if let ExprKind::Path(ref qpath) = path_expr.node {

clippy_lints/src/utils/hir_utils.rs

@@ -73,6 +73,7 @@ impl<'a, 'tcx: 'a> SpanlessEq<'a, 'tcx> {
             && both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
     }
 
+    #[allow(clippy::similar_names)]
     pub fn eq_expr(&mut self, left: &Expr, right: &Expr) -> bool {
         if self.ignore_fn && differing_macro_contexts(left.span, right.span) {
             return false;
@@ -208,6 +209,7 @@ impl<'a, 'tcx: 'a> SpanlessEq<'a, 'tcx> {
         }
     }
 
+    #[allow(clippy::similar_names)]
     fn eq_qpath(&mut self, left: &QPath, right: &QPath) -> bool {
         match (left, right) {
             (&QPath::Resolved(ref lty, ref lpath), &QPath::Resolved(ref rty, ref rpath)) => {
@@ -262,6 +264,7 @@ impl<'a, 'tcx: 'a> SpanlessEq<'a, 'tcx> {
         self.eq_ty_kind(&left.node, &right.node)
     }
 
+    #[allow(clippy::similar_names)]
     pub fn eq_ty_kind(&mut self, left: &TyKind, right: &TyKind) -> bool {
         match (left, right) {
             (&TyKind::Slice(ref l_vec), &TyKind::Slice(ref r_vec)) => self.eq_ty(l_vec, r_vec),

clippy_lints/src/utils/inspector.rs

@@ -166,6 +166,7 @@ fn print_decl(cx: &LateContext<'_, '_>, decl: &hir::Decl) {
     }
 }
 
+#[allow(clippy::similar_names)]
 fn print_expr(cx: &LateContext<'_, '_>, expr: &hir::Expr, indent: usize) {
     let ind = "  ".repeat(indent);
     println!("{}+", ind);
@@ -424,6 +425,7 @@ fn print_item(cx: &LateContext<'_, '_>, item: &hir::Item) {
     }
 }
 
+#[allow(clippy::similar_names)]
 fn print_pat(cx: &LateContext<'_, '_>, pat: &hir::Pat, indent: usize) {
     let ind = "  ".repeat(indent);
     println!("{}+", ind);

clippy_lints/src/utils/usage.rs

@@ -54,6 +54,7 @@ struct MutVarsDelegate {
 }
 
 impl<'tcx> MutVarsDelegate {
+    #[allow(clippy::similar_names)]
     fn update(&mut self, cat: &'tcx Categorization<'_>) {
         match *cat {
             Categorization::Local(id) => {