add some tests for tuples with type annotations

Author: y21

tests/ui/map_identity.fixed

@@ -30,13 +30,18 @@ fn issue7189() {
 
     let y = [(1, 2, (3, (4,))), (5, 6, (7, (8,)))];
     let _ = y.iter();
+    let _ = y
+        .iter();
 
     // should not lint
     let _ = x.iter().map(|(x, y)| (x, y, y));
     let _ = x.iter().map(|(x, _y)| (x,));
     let _ = x.iter().map(|(x, _)| (x,));
     let _ = x.iter().map(|(x, ..)| (x,));
     let _ = y.iter().map(|(x, y, (z, _))| (x, y, (z, z)));
+    let _ = y
+        .iter()
+        .map(|(x, y, (z, _)): &(i32, i32, (i32, (i32,)))| (x, y, (z, z)));
 }
 
 fn not_identity(x: &u16) -> u16 {

tests/ui/map_identity.rs

@@ -34,13 +34,19 @@ fn issue7189() {
 
     let y = [(1, 2, (3, (4,))), (5, 6, (7, (8,)))];
     let _ = y.iter().map(|(x, y, (z, (w,)))| (x, y, (z, (w,))));
+    let _ = y
+        .iter()
+        .map(|(x, y, (z, (w,))): &(i32, i32, (i32, (i32,)))| (x, y, (z, (w,))));
 
     // should not lint
     let _ = x.iter().map(|(x, y)| (x, y, y));
     let _ = x.iter().map(|(x, _y)| (x,));
     let _ = x.iter().map(|(x, _)| (x,));
     let _ = x.iter().map(|(x, ..)| (x,));
     let _ = y.iter().map(|(x, y, (z, _))| (x, y, (z, z)));
+    let _ = y
+        .iter()
+        .map(|(x, y, (z, _)): &(i32, i32, (i32, (i32,)))| (x, y, (z, z)));
 }
 
 fn not_identity(x: &u16) -> u16 {

tests/ui/map_identity.stderr

@@ -66,5 +66,13 @@ error: unnecessary map of the identity function
 LL |     let _ = y.iter().map(|(x, y, (z, (w,)))| (x, y, (z, (w,))));
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the call to `map`
 
-error: aborting due to 10 previous errors
+error: unnecessary map of the identity function
+  --> $DIR/map_identity.rs:38:16
+   |
+LL |           .iter()
+   |  ________________^
+LL | |         .map(|(x, y, (z, (w,))): &(i32, i32, (i32, (i32,)))| (x, y, (z, (w,))));
+   | |_______________________________________________________________________________^ help: remove the call to `map`
+
+error: aborting due to 11 previous errors