Add clippy::unconditional_recursion to ./x clippy ci

The clippy lint catches some things that rustc's equivalent builtin lint does not, for example #146940: error: function cannot return without recursing --> library/std/src/path.rs:3428:5 | 3428 | / fn eq(&self, other: &String) -> bool { 3429 | | self == &*other 3430 | | } | |_____^ | note: recursive call site --> library/std/src/path.rs:3429:9 | 3429 | self == &*other | ^^^^^^^^^^^^^^^ = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unconditional_recursion = note: requested on the command line with `-D clippy::unconditional-recursion`

Author: cuviper

src/bootstrap/src/core/build_steps/clippy.rs

@@ -564,6 +564,7 @@ impl Step for CI {
  "clippy::same_item_push".into(),
  "clippy::single_char_add_str".into(),
  "clippy::to_string_in_format_args".into(),
+ "clippy::unconditional_recursion".into(),
  ],
  forbid: vec![],
  };
@@ -591,6 +592,7 @@ impl Step for CI {
  "clippy::same_item_push".into(),
  "clippy::single_char_add_str".into(),
  "clippy::to_string_in_format_args".into(),
+ "clippy::unconditional_recursion".into(),
  ],
  forbid: vec![],
  };