add test for Result

Author: J-ZhengLi

tests/ui/option_if_let_else.fixed

@@ -177,4 +177,14 @@ fn main() {
     // issue #8492
     let _ = s.map_or(1, |string| string.len());
     let _ = Some(10).map_or(5, |a| a + 1);
+
+    let res: Result<i32, i32> = Ok(5);
+    let _ = match res {
+        Ok(a) => a + 1,
+        _ => 1,
+    };
+    let _ = match res {
+        Err(_) => 1,
+        Ok(a) => a + 1,
+    };
 }

tests/ui/option_if_let_else.rs

@@ -212,4 +212,14 @@ fn main() {
         Some(a) => a + 1,
         None => 5,
     };
+
+    let res: Result<i32, i32> = Ok(5);
+    let _ = match res {
+        Ok(a) => a + 1,
+        _ => 1,
+    };
+    let _ = match res {
+        Err(_) => 1,
+        Ok(a) => a + 1,
+    };
 }