Fix FN in iter_cloned_collect with a large array

tests/ui/iter_cloned_collect.fixed

@@ -19,4 +19,8 @@ fn main() {
         let _: Vec<u8> = std::ffi::CStr::from_ptr(std::ptr::null())
             .to_bytes().to_vec();
     }
+
+    // Issue #6808
+    let arr: [u8; 64] = [0; 64];
+    let _: Vec<_> = arr.to_vec();
 }

tests/ui/iter_cloned_collect.rs

@@ -22,4 +22,8 @@ fn main() {
             .cloned()
             .collect();
     }
+
+    // Issue #6808
+    let arr: [u8; 64] = [0; 64];
+    let _: Vec<_> = arr.iter().cloned().collect();
 }

tests/ui/iter_cloned_collect.stderr

@@ -22,5 +22,11 @@ LL | |             .cloned()
 LL | |             .collect();
    | |______________________^ help: try: `.to_vec()`
 
-error: aborting due to 3 previous errors
+error: called `iter().cloned().collect()` on a slice to create a `Vec`. Calling `to_vec()` is both faster and more readable
+  --> $DIR/iter_cloned_collect.rs:28:24
+   |
+LL |     let _: Vec<_> = arr.iter().cloned().collect();
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `.to_vec()`
+
+error: aborting due to 4 previous errors