remove unnecessary uses of clone

compiler/rustc_ast/src/token.rs

@@ -114,7 +114,7 @@ impl Lit {
                 if let NtExpr(expr) | NtLiteral(expr) = &**nt
                 && let ast::ExprKind::Lit(token_lit) = expr.kind =>
             {
-                Some(token_lit.clone())
+                Some(token_lit)
             }
             _ => None,
         }

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -630,7 +630,7 @@ fn check_incompatible_features(sess: &Session) {
             {
                 let spans = vec![f1_span, f2_span];
                 sess.struct_span_err(
-                    spans.clone(),
+                    spans,
                     &format!(
                         "features `{}` and `{}` are incompatible, using them at the same time \
                         is not allowed",

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -745,7 +745,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             err.span_suggestion_verbose(
                 span.shrink_to_hi(),
                 "consider cloning the value if the performance cost is acceptable",
-                ".clone()".to_string(),
+                ".clone()",
                 Applicability::MachineApplicable,
             );
         }

compiler/rustc_builtin_macros/src/alloc_error_handler.rs

@@ -32,7 +32,7 @@ pub fn expand(
             (item, true, ecx.with_def_site_ctxt(fn_kind.sig.span))
         } else {
             ecx.sess.parse_sess.span_diagnostic.span_err(item.span(), "alloc_error_handler must be a function");
-            return vec![orig_item.clone()];
+            return vec![orig_item];
         };
 
     // Generate a bunch of new items using the AllocFnFactory

compiler/rustc_builtin_macros/src/concat_bytes.rs

@@ -196,7 +196,7 @@ pub fn expand_concat_bytes(
         }
     }
     if !missing_literals.is_empty() {
-        let mut err = cx.struct_span_err(missing_literals.clone(), "expected a byte literal");
+        let mut err = cx.struct_span_err(missing_literals, "expected a byte literal");
         err.note("only byte literals (like `b\"foo\"`, `b's'`, and `[3, 4, 5]`) can be passed to `concat_bytes!()`");
         err.emit();
         return base::MacEager::expr(DummyResult::raw_expr(sp, true));

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -206,7 +206,7 @@ pub(crate) fn run_thin(
 }
 
 pub(crate) fn prepare_thin(module: ModuleCodegen<ModuleLlvm>) -> (String, ThinBuffer) {
-    let name = module.name.clone();
+    let name = module.name;
     let buffer = ThinBuffer::new(module.module_llvm.llmod(), true);
     (name, buffer)
 }

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs

@@ -330,7 +330,7 @@ pub fn suggest_new_region_bound(
                             Applicability::MaybeIncorrect,
                         );
                     }
-                    if let Some((param_span, param_ty)) = param.clone() {
+                    if let Some((param_span, ref param_ty)) = param {
                         err.span_suggestion_verbose(
                             param_span,
                             add_static_bound,