add more tests to unnecessary_find_map and unnecessary_filter_map

Author: y21

tests/ui/unnecessary_filter_map.rs

@@ -148,3 +148,9 @@ mod comment_1052978898 {
         })
     }
 }
+
+fn issue11260() {
+    // #11260 is about unnecessary_find_map, but the fix also kind of applies to
+    // unnecessary_filter_map
+    let _x = std::iter::once(1).filter_map(|n| (n > 1).then_some(n));
+}

tests/ui/unnecessary_filter_map.stderr

@@ -34,5 +34,11 @@ error: this `.filter_map` can be written more simply using `.map`
 LL |     let _ = (0..4).filter_map(|x| Some(x + 1));
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 4 previous errors
+error: this `.filter_map` can be written more simply using `.filter`
+  --> $DIR/unnecessary_filter_map.rs:155:14
+   |
+LL |     let _x = std::iter::once(1).filter_map(|n| (n > 1).then_some(n));
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 5 previous errors
 

tests/ui/unnecessary_find_map.rs

@@ -23,5 +23,7 @@ fn find_map_none_changes_item_type() -> Option<bool> {
 }
 
 fn issue11260() {
+    let y = Some(1);
     let _x = std::iter::once(1).find_map(|n| (n > 1).then_some(n));
+    let _x = std::iter::once(1).find_map(|n| (n > 1).then_some(y)); // different option, so can't be just `.find()`
 }

tests/ui/unnecessary_find_map.stderr

@@ -35,7 +35,7 @@ LL |     let _ = (0..4).find_map(|x| Some(x + 1));
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: this `.find_map` can be written more simply using `.find`
-  --> $DIR/unnecessary_find_map.rs:26:14
+  --> $DIR/unnecessary_find_map.rs:27:14
    |
 LL |     let _x = std::iter::once(1).find_map(|n| (n > 1).then_some(n));
    |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^