Merge pull request rust-lang#1355 from matthiaskrgr/clippy_perf

clippy::perf fixes

Author: bjorn3

src/base.rs

@@ -192,7 +192,7 @@ pub(crate) fn compile_fn(
                         let pass_times = cranelift_codegen::timing::take_current();
                         // Replace newlines with | as measureme doesn't allow control characters like
                         // newlines inside strings.
-                        recorder.record_arg(format!("{}", pass_times).replace("\n", " | "));
+                        recorder.record_arg(format!("{}", pass_times).replace('\n', " | "));
                         recording_args = true;
                     },
                 )

src/global_asm.rs

@@ -125,7 +125,7 @@ pub(crate) fn compile_global_asm(
     let output_object_file = config.output_filenames.temp_path(OutputType::Object, Some(cgu_name));
 
     // Assemble `global_asm`
-    let global_asm_object_file = add_file_stem_postfix(output_object_file.clone(), ".asm");
+    let global_asm_object_file = add_file_stem_postfix(output_object_file, ".asm");
     let mut child = Command::new(&config.assembler)
         .arg("-o")
         .arg(&global_asm_object_file)

src/pretty_clif.rs

@@ -245,7 +245,7 @@ pub(crate) fn write_clif_file(
         for flag in isa.flags().iter() {
             writeln!(file, "set {}", flag)?;
         }
-        write!(file, "target {}", isa.triple().architecture.to_string())?;
+        write!(file, "target {}", isa.triple().architecture)?;
         for isa_flag in isa.isa_flags().iter() {
             write!(file, " {}", isa_flag)?;
         }