Improve needless_borrow lint.

* Lint when a borrow is auto dereferenced more than once
* Lint when the expression is used as the expression of a block for a match arm

Moves `needless_borrow` and `ref_binding_to_reference` to `dereference`
lint pass in preperation for `explicit_auto_deref` lint.

Author: Jarcho

clippy_lints/src/dereference.rs

@@ -33,6 +33,7 @@ store.register_group(true, "clippy::all", Some("clippy_all"), vec![
     LintId::of(copies::IFS_SAME_COND),
     LintId::of(copies::IF_SAME_THEN_ELSE),
     LintId::of(default::FIELD_REASSIGN_WITH_DEFAULT),
+    LintId::of(dereference::NEEDLESS_BORROW),
     LintId::of(derivable_impls::DERIVABLE_IMPLS),
     LintId::of(derive::DERIVE_HASH_XOR_EQ),
     LintId::of(derive::DERIVE_ORD_XOR_PARTIAL_ORD),
@@ -203,7 +204,6 @@ store.register_group(true, "clippy::all", Some("clippy_all"), vec![
     LintId::of(needless_arbitrary_self_type::NEEDLESS_ARBITRARY_SELF_TYPE),
     LintId::of(needless_bool::BOOL_COMPARISON),
     LintId::of(needless_bool::NEEDLESS_BOOL),
-    LintId::of(needless_borrow::NEEDLESS_BORROW),
     LintId::of(needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE),
     LintId::of(needless_option_as_deref::NEEDLESS_OPTION_AS_DEREF),
     LintId::of(needless_question_mark::NEEDLESS_QUESTION_MARK),

clippy_lints/src/lib.register_all.rs

@@ -92,6 +92,8 @@ store.register_lints(&[
     default::FIELD_REASSIGN_WITH_DEFAULT,
     default_numeric_fallback::DEFAULT_NUMERIC_FALLBACK,
     dereference::EXPLICIT_DEREF_METHODS,
+    dereference::NEEDLESS_BORROW,
+    dereference::REF_BINDING_TO_REFERENCE,
     derivable_impls::DERIVABLE_IMPLS,
     derive::DERIVE_HASH_XOR_EQ,
     derive::DERIVE_ORD_XOR_PARTIAL_ORD,
@@ -356,8 +358,6 @@ store.register_lints(&[
     needless_bitwise_bool::NEEDLESS_BITWISE_BOOL,
     needless_bool::BOOL_COMPARISON,
     needless_bool::NEEDLESS_BOOL,
-    needless_borrow::NEEDLESS_BORROW,
-    needless_borrow::REF_BINDING_TO_REFERENCE,
     needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE,
     needless_continue::NEEDLESS_CONTINUE,
     needless_for_each::NEEDLESS_FOR_EACH,

clippy_lints/src/lib.register_lints.rs

@@ -21,6 +21,7 @@ store.register_group(true, "clippy::pedantic", Some("clippy_pedantic"), vec![
     LintId::of(copy_iterator::COPY_ITERATOR),
     LintId::of(default::DEFAULT_TRAIT_ACCESS),
     LintId::of(dereference::EXPLICIT_DEREF_METHODS),
+    LintId::of(dereference::REF_BINDING_TO_REFERENCE),
     LintId::of(derive::EXPL_IMPL_CLONE_ON_COPY),
     LintId::of(derive::UNSAFE_DERIVE_DESERIALIZE),
     LintId::of(doc::DOC_MARKDOWN),
@@ -68,7 +69,6 @@ store.register_group(true, "clippy::pedantic", Some("clippy_pedantic"), vec![
     LintId::of(misc::USED_UNDERSCORE_BINDING),
     LintId::of(mut_mut::MUT_MUT),
     LintId::of(needless_bitwise_bool::NEEDLESS_BITWISE_BOOL),
-    LintId::of(needless_borrow::REF_BINDING_TO_REFERENCE),
     LintId::of(needless_continue::NEEDLESS_CONTINUE),
     LintId::of(needless_for_each::NEEDLESS_FOR_EACH),
     LintId::of(needless_pass_by_value::NEEDLESS_PASS_BY_VALUE),

clippy_lints/src/lib.register_pedantic.rs

@@ -15,6 +15,7 @@ store.register_group(true, "clippy::style", Some("clippy_style"), vec![
     LintId::of(collapsible_match::COLLAPSIBLE_MATCH),
     LintId::of(comparison_chain::COMPARISON_CHAIN),
     LintId::of(default::FIELD_REASSIGN_WITH_DEFAULT),
+    LintId::of(dereference::NEEDLESS_BORROW),
     LintId::of(doc::MISSING_SAFETY_DOC),
     LintId::of(doc::NEEDLESS_DOCTEST_MAIN),
     LintId::of(enum_variants::ENUM_VARIANT_NAMES),
@@ -81,7 +82,6 @@ store.register_group(true, "clippy::style", Some("clippy_style"), vec![
     LintId::of(misc_early::REDUNDANT_PATTERN),
     LintId::of(mut_mutex_lock::MUT_MUTEX_LOCK),
     LintId::of(mut_reference::UNNECESSARY_MUT_PASSED),
-    LintId::of(needless_borrow::NEEDLESS_BORROW),
     LintId::of(neg_multiply::NEG_MULTIPLY),
     LintId::of(new_without_default::NEW_WITHOUT_DEFAULT),
     LintId::of(non_copy_const::BORROW_INTERIOR_MUTABLE_CONST),

clippy_lints/src/lib.register_style.rs

@@ -297,7 +297,6 @@ mod mutex_atomic;
 mod needless_arbitrary_self_type;
 mod needless_bitwise_bool;
 mod needless_bool;
-mod needless_borrow;
 mod needless_borrowed_ref;
 mod needless_continue;
 mod needless_for_each;
@@ -602,7 +601,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|| Box::new(zero_div_zero::ZeroDiv));
     store.register_late_pass(|| Box::new(mutex_atomic::Mutex));
     store.register_late_pass(|| Box::new(needless_update::NeedlessUpdate));
-    store.register_late_pass(|| Box::new(needless_borrow::NeedlessBorrow::default()));
     store.register_late_pass(|| Box::new(needless_borrowed_ref::NeedlessBorrowedRef));
     store.register_late_pass(|| Box::new(no_effect::NoEffect));
     store.register_late_pass(|| Box::new(temporary_assignment::TemporaryAssignment));