Fix clippy::needless_borrow in the compiler

`x clippy compiler -Aclippy::all -Wclippy::needless_borrow --fix`.

Then I had to remove a few unnecessary parens and muts that were exposed
now.

compiler/rustc_codegen_llvm/src/abi.rs

@@ -493,7 +493,7 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
             PassMode::Cast { cast, pad_i32: _ } => {
                 cast.attrs.apply_attrs_to_callsite(
                     llvm::AttributePlace::ReturnValue,
-                    &bx.cx,
+                    bx.cx,
                     callsite,
                 );
             }

compiler/rustc_codegen_llvm/src/allocator.rs

@@ -67,7 +67,7 @@ pub(crate) unsafe fn codegen(
         llcx,
         llmod,
         "__rust_alloc_error_handler",
-        &alloc_error_handler_name(alloc_error_handler_kind),
+        alloc_error_handler_name(alloc_error_handler_kind),
         &[usize, usize], // size, align
         None,
         true,

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -136,7 +136,7 @@ fn instrument_function_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> SmallVec<[&'ll Attr
         attrs.push(llvm::CreateAttrStringValue(
             cx.llcx,
             "instrument-function-entry-inlined",
-            &mcount_name,
+            mcount_name,
         ));
     }
     if let Some(options) = &cx.sess().opts.unstable_opts.instrument_xray {
@@ -459,7 +459,7 @@ pub fn from_fn_attrs<'ll, 'tcx>(
         // If this function is an import from the environment but the wasm
         // import has a specific module/name, apply them here.
         if let Some(module) = wasm_import_module(cx.tcx, instance.def_id()) {
-            to_add.push(llvm::CreateAttrStringValue(cx.llcx, "wasm-import-module", &module));
+            to_add.push(llvm::CreateAttrStringValue(cx.llcx, "wasm-import-module", module));
 
             let name =
                 codegen_fn_attrs.link_name.unwrap_or_else(|| cx.tcx.item_name(instance.def_id()));

compiler/rustc_codegen_llvm/src/back/archive.rs

@@ -68,7 +68,7 @@ impl<'a> ArchiveBuilder<'a> for LlvmArchiveBuilder<'a> {
     ) -> io::Result<()> {
         let mut archive = archive.to_path_buf();
         if self.sess.target.llvm_target.contains("-apple-macosx") {
-            if let Some(new_archive) = try_extract_macho_fat_archive(&self.sess, &archive)? {
+            if let Some(new_archive) = try_extract_macho_fat_archive(self.sess, &archive)? {
                 archive = new_archive
             }
         }

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -124,7 +124,7 @@ pub fn create_target_machine(tcx: TyCtxt<'_>, mod_name: &str) -> OwnedTargetMach
     let config = TargetMachineFactoryConfig { split_dwarf_file, output_obj_file };
 
     target_machine_factory(
-        &tcx.sess,
+        tcx.sess,
         tcx.backend_optimization_level(()),
         tcx.global_backend_features(()),
     )(config)
@@ -1106,7 +1106,7 @@ fn record_llvm_cgu_instructions_stats(prof: &SelfProfilerRef, llmod: &llvm::Modu
     }
 
     let raw_stats =
-        llvm::build_string(|s| unsafe { llvm::LLVMRustModuleInstructionStats(&llmod, s) })
+        llvm::build_string(|s| unsafe { llvm::LLVMRustModuleInstructionStats(llmod, s) })
             .expect("cannot get module instruction stats");
 
     #[derive(serde::Deserialize)]

compiler/rustc_codegen_llvm/src/callee.rs

@@ -62,7 +62,7 @@ pub fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'tcx>) ->
             // exemption for MinGW for backwards compatibility.
             let llfn = cx.declare_fn(
                 &common::i686_decorated_name(
-                    &dllimport,
+                    dllimport,
                     common::is_mingw_gnu_toolchain(&tcx.sess.target),
                     true,
                 ),

compiler/rustc_codegen_llvm/src/consts.rs

@@ -187,7 +187,7 @@ fn check_and_apply_linkage<'ll, 'tcx>(
     {
         cx.declare_global(
             &common::i686_decorated_name(
-                &dllimport,
+                dllimport,
                 common::is_mingw_gnu_toolchain(&cx.tcx.sess.target),
                 true,
             ),

compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs

@@ -176,7 +176,7 @@ impl GlobalFileTable {
         // compilation directory can be combined with the relative paths
         // to get absolute paths, if needed.
         use rustc_session::RemapFileNameExt;
-        let working_dir: &str = &tcx.sess.opts.working_dir.for_codegen(&tcx.sess).to_string_lossy();
+        let working_dir: &str = &tcx.sess.opts.working_dir.for_codegen(tcx.sess).to_string_lossy();
 
         llvm::build_byte_buffer(|buffer| {
             coverageinfo::write_filenames_section_to_buffer(

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -853,7 +853,7 @@ pub fn build_compile_unit_di_node<'ll, 'tcx>(
 
     use rustc_session::RemapFileNameExt;
     let name_in_debuginfo = name_in_debuginfo.to_string_lossy();
-    let work_dir = tcx.sess.opts.working_dir.for_codegen(&tcx.sess).to_string_lossy();
+    let work_dir = tcx.sess.opts.working_dir.for_codegen(tcx.sess).to_string_lossy();
     let flags = "\0";
     let output_filenames = tcx.output_filenames(());
     let split_name = if tcx.sess.target_can_use_split_dwarf() {

compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs

@@ -715,7 +715,7 @@ fn build_union_fields_for_direct_tag_coroutine<'ll, 'tcx>(
                 coroutine_type_and_layout,
                 coroutine_type_di_node,
                 coroutine_layout,
-                &common_upvar_names,
+                common_upvar_names,
             );
 
             let span = coroutine_layout.variant_source_info[variant_index].span;

compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs

@@ -197,7 +197,7 @@ pub(super) fn build_coroutine_di_node<'ll, 'tcx>(
                                 coroutine_type_and_layout,
                                 coroutine_type_di_node,
                                 coroutine_layout,
-                                &common_upvar_names,
+                                common_upvar_names,
                             ),
                         source_info,
                     }

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -537,8 +537,7 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str
                 if feature_state.is_none() {
                     let rust_feature = supported_features.iter().find_map(|&(rust_feature, _)| {
                         let llvm_features = to_llvm_features(sess, rust_feature);
-                        if llvm_features.contains(&feature)
-                            && !llvm_features.contains(&rust_feature)
+                        if llvm_features.contains(feature) && !llvm_features.contains(rust_feature)
                         {
                             Some(rust_feature)
                         } else {