New lint: unnecessary_semicolon

tests/ui/unnecessary_semicolon.fixed

@@ -0,0 +1,32 @@
+#![warn(clippy::unnecessary_semicolon)]
+#![feature(postfix_match)]
+
+fn no_lint(mut x: u32) -> Option<u32> {
+    Some(())?;
+
+    {
+        let y = 3;
+        dbg!(x + y)
+    };
+
+    {
+        let (mut a, mut b) = (10, 20);
+        (a, b) = (b + 1, a + 1);
+    }
+
+    Some(0)
+}
+
+fn main() {
+    let mut a = 3;
+    if a == 2 {
+        println!("This is weird");
+    }
+    //~^ ERROR: unnecessary semicolon
+
+    a.match {
+        3 => println!("three"),
+        _ => println!("not three"),
+    }
+    //~^ ERROR: unnecessary semicolon
+}

tests/ui/unnecessary_semicolon.rs

@@ -0,0 +1,32 @@
+#![warn(clippy::unnecessary_semicolon)]
+#![feature(postfix_match)]
+
+fn no_lint(mut x: u32) -> Option<u32> {
+    Some(())?;
+
+    {
+        let y = 3;
+        dbg!(x + y)
+    };
+
+    {
+        let (mut a, mut b) = (10, 20);
+        (a, b) = (b + 1, a + 1);
+    }
+
+    Some(0)
+}
+
+fn main() {
+    let mut a = 3;
+    if a == 2 {
+        println!("This is weird");
+    };
+    //~^ ERROR: unnecessary semicolon
+
+    a.match {
+        3 => println!("three"),
+        _ => println!("not three"),
+    };
+    //~^ ERROR: unnecessary semicolon
+}

tests/ui/unnecessary_semicolon.stderr

@@ -0,0 +1,17 @@
+error: unnecessary semicolon
+  --> tests/ui/unnecessary_semicolon.rs:24:6
+   |
+LL |     };
+   |      ^ help: remove
+   |
+   = note: `-D clippy::unnecessary-semicolon` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::unnecessary_semicolon)]`
+
+error: unnecessary semicolon
+  --> tests/ui/unnecessary_semicolon.rs:30:6
+   |
+LL |     };
+   |      ^ help: remove
+
+error: aborting due to 2 previous errors
+