Make dogfood tests run in release mode

Author: blyxyas

clippy_dev/src/dogfood.rs

@@ -10,7 +10,8 @@ pub fn dogfood(fix: bool, allow_dirty: bool, allow_staged: bool) {
     cmd.current_dir(clippy_project_root())
         .args(["test", "--test", "dogfood"])
         .args(["--features", "internal"])
-        .args(["--", "dogfood_clippy"]);
+        .args(["--", "dogfood_clippy"])
+        .arg("--release");
 
     let mut dogfood_args = Vec::new();
     if fix {