add byref checking for the guard's local

tests/ui/redundant_guards.fixed

@@ -143,3 +143,44 @@ fn g(opt_s: Option<S>) {
         _ => {},
     }
 }
+
+mod issue11465 {
+    enum A {
+        Foo([u8; 3]),
+    }
+
+    struct B {
+        b: String,
+        c: i32,
+    }
+
+    fn issue11465() {
+        let c = Some(1);
+        match c {
+            Some(1) => {},
+            Some(2) => {},
+            Some(3) => {},
+            _ => {},
+        };
+
+        let enum_a = A::Foo([98, 97, 114]);
+        match enum_a {
+            A::Foo(ref arr) if arr == b"foo" => {},
+            A::Foo(ref arr) if let b"bar" = arr => {},
+            A::Foo(ref arr) if matches!(arr, b"baz") => {},
+            _ => {},
+        };
+
+        let struct_b = B {
+            b: "bar".to_string(),
+            c: 42,
+        };
+        match struct_b {
+            B { ref b, .. } if b == "bar" => {},
+            B { ref c, .. } if c == &1 => {},
+            B { ref c, .. } if let &1 = c => {},
+            B { ref c, .. } if matches!(c, &1) => {},
+            _ => {},
+        }
+    }
+}

tests/ui/redundant_guards.rs

@@ -143,3 +143,44 @@ fn g(opt_s: Option<S>) {
         _ => {},
     }
 }
+
+mod issue11465 {
+    enum A {
+        Foo([u8; 3]),
+    }
+
+    struct B {
+        b: String,
+        c: i32,
+    }
+
+    fn issue11465() {
+        let c = Some(1);
+        match c {
+            Some(ref x) if x == &1 => {},
+            Some(ref x) if let &2 = x => {},
+            Some(ref x) if matches!(x, &3) => {},
+            _ => {},
+        };
+
+        let enum_a = A::Foo([98, 97, 114]);
+        match enum_a {
+            A::Foo(ref arr) if arr == b"foo" => {},
+            A::Foo(ref arr) if let b"bar" = arr => {},
+            A::Foo(ref arr) if matches!(arr, b"baz") => {},
+            _ => {},
+        };
+
+        let struct_b = B {
+            b: "bar".to_string(),
+            c: 42,
+        };
+        match struct_b {
+            B { ref b, .. } if b == "bar" => {},
+            B { ref c, .. } if c == &1 => {},
+            B { ref c, .. } if let &1 = c => {},
+            B { ref c, .. } if matches!(c, &1) => {},
+            _ => {},
+        }
+    }
+}

tests/ui/redundant_guards.stderr

@@ -94,5 +94,41 @@ LL -         x if matches!(x, Some(0)) => ..,
 LL +         Some(0) => ..,
    |
 
-error: aborting due to 8 previous errors
+error: redundant guard
+  --> $DIR/redundant_guards.rs:160:28
+   |
+LL |             Some(ref x) if x == &1 => {},
+   |                            ^^^^^^^
+   |
+help: try
+   |
+LL -             Some(ref x) if x == &1 => {},
+LL +             Some(1) => {},
+   |
+
+error: redundant guard
+  --> $DIR/redundant_guards.rs:161:28
+   |
+LL |             Some(ref x) if let &2 = x => {},
+   |                            ^^^^^^^^^^
+   |
+help: try
+   |
+LL -             Some(ref x) if let &2 = x => {},
+LL +             Some(2) => {},
+   |
+
+error: redundant guard
+  --> $DIR/redundant_guards.rs:162:28
+   |
+LL |             Some(ref x) if matches!(x, &3) => {},
+   |                            ^^^^^^^^^^^^^^^
+   |
+help: try
+   |
+LL -             Some(ref x) if matches!(x, &3) => {},
+LL +             Some(3) => {},
+   |
+
+error: aborting due to 11 previous errors