Add clippy suggestions (#6203)

* add clippy suggestions

* revert &/ref change

* Update cranelift/isle/isle/src/parser.rs

Co-authored-by: Jamey Sharp <jamey@minilop.net>

---------

Co-authored-by: Jamey Sharp <jamey@minilop.net>

crates/cache/build.rs

@@ -2,7 +2,7 @@ use std::process::Command;
 use std::str;
 
 fn main() {
-    let git_rev = match Command::new("git").args(&["rev-parse", "HEAD"]).output() {
+    let git_rev = match Command::new("git").args(["rev-parse", "HEAD"]).output() {
         Ok(output) => str::from_utf8(&output.stdout).unwrap().trim().to_string(),
         Err(_) => env!("CARGO_PKG_VERSION").to_string(),
     };