feat(lint): add default_iter_empty

Update description in clippy_lints/src/default_iter_empty.rs

Co-authored-by: Fridtjof Stoldt <xFrednet@gmail.com>

Update clippy_lints/src/default_iter_empty.rs

Co-authored-by: Alex Macleod <alex@macleod.io>

Update clippy_lints/src/default_iter_empty.rs

Co-authored-by: Alex Macleod <alex@macleod.io>

renamed default_iter_empty to default_instead_of_iter_empty

Avoid duplicate messages

add tests for regression

rewrite 'Why is this bad?'

cargo dev fmt

delete default_iter_empty lint in renamed_lint.rs

rewrite a message in the suggestion

cargo dev update_lints --check

clippy_lints/src/lib.rs

@@ -199,6 +199,7 @@ mod crate_in_macro_def;
 mod create_dir;
 mod dbg_macro;
 mod default;
+mod default_instead_of_iter_empty;
 mod default_numeric_fallback;
 mod default_union_representation;
 mod dereference;
@@ -910,6 +911,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|| Box::new(mismatching_type_param_order::TypeParamMismatch));
     store.register_late_pass(|| Box::new(as_underscore::AsUnderscore));
     store.register_late_pass(|| Box::new(read_zero_byte_vec::ReadZeroByteVec));
+    store.register_late_pass(|| Box::new(default_instead_of_iter_empty::DefaultIterEmpty));
     // add lints here, do not remove this comment, it's used in `new_lint`
 }