Remove some unused `#![feature]`s

12 files changed, 34 insertions, 40 deletions

diff --git a/tests/compile-test.rs b/tests/compile-test.rs
index 6d391bd622a..78b27e2f613 100644
--- a/tests/compile-test.rs
+++ b/tests/compile-test.rs
@@ -1,4 +1,4 @@
-#![feature(rustc_private, let_chains)]
+#![feature(rustc_private)]
 #![warn(rust_2018_idioms, unused_lifetimes)]
 #![allow(unused_extern_crates)]
 
diff --git a/tests/ui/bool_to_int_with_if.fixed b/tests/ui/bool_to_int_with_if.fixed
index ed6141244b4..7fa7c016f93 100644
--- a/tests/ui/bool_to_int_with_if.fixed
+++ b/tests/ui/bool_to_int_with_if.fixed
@@ -1,4 +1,3 @@
-#![feature(let_chains)]
 #![warn(clippy::bool_to_int_with_if)]
 #![allow(unused, dead_code, clippy::unnecessary_operation, clippy::no_effect)]
 
diff --git a/tests/ui/bool_to_int_with_if.rs b/tests/ui/bool_to_int_with_if.rs
index 3f1f1c766e4..2295d6f1362 100644
--- a/tests/ui/bool_to_int_with_if.rs
+++ b/tests/ui/bool_to_int_with_if.rs
@@ -1,4 +1,3 @@
-#![feature(let_chains)]
 #![warn(clippy::bool_to_int_with_if)]
 #![allow(unused, dead_code, clippy::unnecessary_operation, clippy::no_effect)]
 
diff --git a/tests/ui/bool_to_int_with_if.stderr b/tests/ui/bool_to_int_with_if.stderr
index 94089bc6dc8..e4ae5730414 100644
--- a/tests/ui/bool_to_int_with_if.stderr
+++ b/tests/ui/bool_to_int_with_if.stderr
@@ -1,5 +1,5 @@
 error: boolean to int conversion using if
-  --> tests/ui/bool_to_int_with_if.rs:14:5
+  --> tests/ui/bool_to_int_with_if.rs:13:5
    |
 LL | /     if a {
 LL | |
@@ -14,7 +14,7 @@ LL | |     };
    = help: to override `-D warnings` add `#[allow(clippy::bool_to_int_with_if)]`
 
 error: boolean to int conversion using if
-  --> tests/ui/bool_to_int_with_if.rs:20:5
+  --> tests/ui/bool_to_int_with_if.rs:19:5
    |
 LL | /     if a {
 LL | |
@@ -27,7 +27,7 @@ LL | |     };
    = note: `!a as i32` or `(!a).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> tests/ui/bool_to_int_with_if.rs:26:5
+  --> tests/ui/bool_to_int_with_if.rs:25:5
    |
 LL | /     if !a {
 LL | |
@@ -40,7 +40,7 @@ LL | |     };
    = note: `!a as i32` or `(!a).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> tests/ui/bool_to_int_with_if.rs:32:5
+  --> tests/ui/bool_to_int_with_if.rs:31:5
    |
 LL | /     if a || b {
 LL | |
@@ -53,7 +53,7 @@ LL | |     };
    = note: `(a || b) as i32` or `(a || b).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> tests/ui/bool_to_int_with_if.rs:38:5
+  --> tests/ui/bool_to_int_with_if.rs:37:5
    |
 LL | /     if cond(a, b) {
 LL | |
@@ -66,7 +66,7 @@ LL | |     };
    = note: `cond(a, b) as i32` or `cond(a, b).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> tests/ui/bool_to_int_with_if.rs:44:5
+  --> tests/ui/bool_to_int_with_if.rs:43:5
    |
 LL | /     if x + y < 4 {
 LL | |
@@ -79,7 +79,7 @@ LL | |     };
    = note: `(x + y < 4) as i32` or `(x + y < 4).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> tests/ui/bool_to_int_with_if.rs:54:12
+  --> tests/ui/bool_to_int_with_if.rs:53:12
    |
 LL |       } else if b {
    |  ____________^
@@ -93,7 +93,7 @@ LL | |     };
    = note: `b as i32` or `b.into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> tests/ui/bool_to_int_with_if.rs:64:12
+  --> tests/ui/bool_to_int_with_if.rs:63:12
    |
 LL |       } else if b {
    |  ____________^
@@ -107,7 +107,7 @@ LL | |     };
    = note: `!b as i32` or `(!b).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> tests/ui/bool_to_int_with_if.rs:130:5
+  --> tests/ui/bool_to_int_with_if.rs:129:5
    |
 LL |     if a { 1 } else { 0 }
    |     ^^^^^^^^^^^^^^^^^^^^^ help: replace with from: `u8::from(a)`
@@ -115,7 +115,7 @@ LL |     if a { 1 } else { 0 }
    = note: `a as u8` or `a.into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> tests/ui/bool_to_int_with_if.rs:174:13
+  --> tests/ui/bool_to_int_with_if.rs:173:13
    |
 LL |     let _ = if dbg!(4 > 0) { 1 } else { 0 };
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with from: `i32::from(dbg!(4 > 0))`
@@ -123,7 +123,7 @@ LL |     let _ = if dbg!(4 > 0) { 1 } else { 0 };
    = note: `dbg!(4 > 0) as i32` or `dbg!(4 > 0).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> tests/ui/bool_to_int_with_if.rs:177:18
+  --> tests/ui/bool_to_int_with_if.rs:176:18
    |
 LL |     let _ = dbg!(if 4 > 0 { 1 } else { 0 });
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with from: `i32::from(4 > 0)`
diff --git a/tests/ui/comparison_to_empty.fixed b/tests/ui/comparison_to_empty.fixed
index dfbb6168384..7a71829dd62 100644
--- a/tests/ui/comparison_to_empty.fixed
+++ b/tests/ui/comparison_to_empty.fixed
@@ -1,6 +1,5 @@
 #![warn(clippy::comparison_to_empty)]
 #![allow(clippy::borrow_deref_ref, clippy::needless_if, clippy::useless_vec)]
-#![feature(let_chains)]
 
 fn main() {
     // Disallow comparisons to empty
diff --git a/tests/ui/comparison_to_empty.rs b/tests/ui/comparison_to_empty.rs
index 61cdb2bbe9f..5d213a09e81 100644
--- a/tests/ui/comparison_to_empty.rs
+++ b/tests/ui/comparison_to_empty.rs
@@ -1,6 +1,5 @@
 #![warn(clippy::comparison_to_empty)]
 #![allow(clippy::borrow_deref_ref, clippy::needless_if, clippy::useless_vec)]
-#![feature(let_chains)]
 
 fn main() {
     // Disallow comparisons to empty
diff --git a/tests/ui/comparison_to_empty.stderr b/tests/ui/comparison_to_empty.stderr
index 00a50430a3e..deb3e938878 100644
--- a/tests/ui/comparison_to_empty.stderr
+++ b/tests/ui/comparison_to_empty.stderr
@@ -1,5 +1,5 @@
 error: comparison to empty slice
-  --> tests/ui/comparison_to_empty.rs:8:13
+  --> tests/ui/comparison_to_empty.rs:7:13
    |
 LL |     let _ = s == "";
    |             ^^^^^^^ help: using `is_empty` is clearer and more explicit: `s.is_empty()`
@@ -8,73 +8,73 @@ LL |     let _ = s == "";
    = help: to override `-D warnings` add `#[allow(clippy::comparison_to_empty)]`
 
 error: comparison to empty slice
-  --> tests/ui/comparison_to_empty.rs:10:13
+  --> tests/ui/comparison_to_empty.rs:9:13
    |
 LL |     let _ = s != "";
    |             ^^^^^^^ help: using `!is_empty` is clearer and more explicit: `!s.is_empty()`
 
 error: comparison to empty slice
-  --> tests/ui/comparison_to_empty.rs:14:13
+  --> tests/ui/comparison_to_empty.rs:13:13
    |
 LL |     let _ = v == [];
    |             ^^^^^^^ help: using `is_empty` is clearer and more explicit: `v.is_empty()`
 
 error: comparison to empty slice
-  --> tests/ui/comparison_to_empty.rs:16:13
+  --> tests/ui/comparison_to_empty.rs:15:13
    |
 LL |     let _ = v != [];
    |             ^^^^^^^ help: using `!is_empty` is clearer and more explicit: `!v.is_empty()`
 
 error: comparison to empty slice using `if let`
-  --> tests/ui/comparison_to_empty.rs:18:8
+  --> tests/ui/comparison_to_empty.rs:17:8
    |
 LL |     if let [] = &*v {}
    |        ^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `(*v).is_empty()`
 
 error: comparison to empty slice using `if let`
-  --> tests/ui/comparison_to_empty.rs:21:8
+  --> tests/ui/comparison_to_empty.rs:20:8
    |
 LL |     if let [] = s {}
    |        ^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `s.is_empty()`
 
 error: comparison to empty slice using `if let`
-  --> tests/ui/comparison_to_empty.rs:23:8
+  --> tests/ui/comparison_to_empty.rs:22:8
    |
 LL |     if let [] = &*s {}
    |        ^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `s.is_empty()`
 
 error: comparison to empty slice using `if let`
-  --> tests/ui/comparison_to_empty.rs:25:8
+  --> tests/ui/comparison_to_empty.rs:24:8
    |
 LL |     if let [] = &*s
    |        ^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `s.is_empty()`
 
 error: comparison to empty slice
-  --> tests/ui/comparison_to_empty.rs:27:12
+  --> tests/ui/comparison_to_empty.rs:26:12
    |
 LL |         && s == []
    |            ^^^^^^^ help: using `is_empty` is clearer and more explicit: `s.is_empty()`
 
 error: comparison to empty slice
-  --> tests/ui/comparison_to_empty.rs:48:13
+  --> tests/ui/comparison_to_empty.rs:47:13
    |
 LL |     let _ = s.eq("");
    |             ^^^^^^^^ help: using `is_empty` is clearer and more explicit: `s.is_empty()`
 
 error: comparison to empty slice
-  --> tests/ui/comparison_to_empty.rs:50:13
+  --> tests/ui/comparison_to_empty.rs:49:13
    |
 LL |     let _ = s.ne("");
    |             ^^^^^^^^ help: using `!is_empty` is clearer and more explicit: `!s.is_empty()`
 
 error: comparison to empty slice
-  --> tests/ui/comparison_to_empty.rs:53:13
+  --> tests/ui/comparison_to_empty.rs:52:13
    |
 LL |     let _ = v.eq(&[]);
    |             ^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `v.is_empty()`
 
 error: comparison to empty slice
-  --> tests/ui/comparison_to_empty.rs:55:13
+  --> tests/ui/comparison_to_empty.rs:54:13
    |
 LL |     let _ = v.ne(&[]);
    |             ^^^^^^^^^ help: using `!is_empty` is clearer and more explicit: `!v.is_empty()`
diff --git a/tests/ui/needless_if.fixed b/tests/ui/needless_if.fixed
index 347dbff7c59..c839156bed9 100644
--- a/tests/ui/needless_if.fixed
+++ b/tests/ui/needless_if.fixed
@@ -1,5 +1,4 @@
 //@aux-build:proc_macros.rs
-#![feature(let_chains)]
 #![allow(
     clippy::blocks_in_conditions,
     clippy::if_same_then_else,
diff --git a/tests/ui/needless_if.rs b/tests/ui/needless_if.rs
index 5e0f2a14408..11103af5c55 100644
--- a/tests/ui/needless_if.rs
+++ b/tests/ui/needless_if.rs
@@ -1,5 +1,4 @@
 //@aux-build:proc_macros.rs
-#![feature(let_chains)]
 #![allow(
     clippy::blocks_in_conditions,
     clippy::if_same_then_else,
diff --git a/tests/ui/needless_if.stderr b/tests/ui/needless_if.stderr
index 62cdf245944..4b56843bd52 100644
--- a/tests/ui/needless_if.stderr
+++ b/tests/ui/needless_if.stderr
@@ -1,5 +1,5 @@
 error: this `if` branch is empty
-  --> tests/ui/needless_if.rs:27:5
+  --> tests/ui/needless_if.rs:26:5
    |
 LL |     if (true) {}
    |     ^^^^^^^^^^^^ help: you can remove it
@@ -8,13 +8,13 @@ LL |     if (true) {}
    = help: to override `-D warnings` add `#[allow(clippy::needless_if)]`
 
 error: this `if` branch is empty
-  --> tests/ui/needless_if.rs:30:5
+  --> tests/ui/needless_if.rs:29:5
    |
 LL |     if maybe_side_effect() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ help: you can remove it: `maybe_side_effect();`
 
 error: this `if` branch is empty
-  --> tests/ui/needless_if.rs:36:5
+  --> tests/ui/needless_if.rs:35:5
    |
 LL | /     if {
 LL | |
@@ -31,7 +31,7 @@ LL +     });
    |
 
 error: this `if` branch is empty
-  --> tests/ui/needless_if.rs:51:5
+  --> tests/ui/needless_if.rs:50:5
    |
 LL | /     if {
 LL | |
@@ -57,19 +57,19 @@ LL +     } && true);
    |
 
 error: this `if` branch is empty
-  --> tests/ui/needless_if.rs:96:5
+  --> tests/ui/needless_if.rs:95:5
    |
 LL |     if { maybe_side_effect() } {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: you can remove it: `({ maybe_side_effect() });`
 
 error: this `if` branch is empty
-  --> tests/ui/needless_if.rs:99:5
+  --> tests/ui/needless_if.rs:98:5
    |
 LL |     if { maybe_side_effect() } && true {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: you can remove it: `({ maybe_side_effect() } && true);`
 
 error: this `if` branch is empty
-  --> tests/ui/needless_if.rs:104:5
+  --> tests/ui/needless_if.rs:103:5
    |
 LL |     if true {}
    |     ^^^^^^^^^^ help: you can remove it: `true;`
diff --git a/tests/ui/redundant_pattern_matching_option.fixed b/tests/ui/redundant_pattern_matching_option.fixed
index 33a5308bd35..dc9d6491691 100644
--- a/tests/ui/redundant_pattern_matching_option.fixed
+++ b/tests/ui/redundant_pattern_matching_option.fixed
@@ -1,4 +1,4 @@
-#![feature(let_chains, if_let_guard)]
+#![feature(if_let_guard)]
 #![warn(clippy::redundant_pattern_matching)]
 #![allow(
     clippy::needless_bool,
diff --git a/tests/ui/redundant_pattern_matching_option.rs b/tests/ui/redundant_pattern_matching_option.rs
index 60bce2994ea..2e9714ad8e7 100644
--- a/tests/ui/redundant_pattern_matching_option.rs
+++ b/tests/ui/redundant_pattern_matching_option.rs
@@ -1,4 +1,4 @@
-#![feature(let_chains, if_let_guard)]
+#![feature(if_let_guard)]
 #![warn(clippy::redundant_pattern_matching)]
 #![allow(
     clippy::needless_bool,