Add more examples to lexicographic cmp on Iterators.

The most important rule of lexicographical comparison is that two arrays
of equal length will be compared until the first difference occured.

The examples provided only focuses on the second rule that says that the
shorter array will be filled with some T2 that is less than every T.
Which is only possible because of the first rule.

library/core/src/iter/traits/iterator.rs

@@ -3077,6 +3077,7 @@ pub trait Iterator {
     /// assert_eq!([1].iter().lt([1].iter()), false);
     /// assert_eq!([1].iter().lt([1, 2].iter()), true);
     /// assert_eq!([1, 2].iter().lt([1].iter()), false);
+    /// assert_eq!([1, 2].iter().lt([1, 2].iter()), false);
     /// ```
     #[stable(feature = "iter_order", since = "1.5.0")]
     fn lt<I>(self, other: I) -> bool
@@ -3097,6 +3098,7 @@ pub trait Iterator {
     /// assert_eq!([1].iter().le([1].iter()), true);
     /// assert_eq!([1].iter().le([1, 2].iter()), true);
     /// assert_eq!([1, 2].iter().le([1].iter()), false);
+    /// assert_eq!([1, 2].iter().le([1, 2].iter()), true);
     /// ```
     #[stable(feature = "iter_order", since = "1.5.0")]
     fn le<I>(self, other: I) -> bool
@@ -3117,6 +3119,7 @@ pub trait Iterator {
     /// assert_eq!([1].iter().gt([1].iter()), false);
     /// assert_eq!([1].iter().gt([1, 2].iter()), false);
     /// assert_eq!([1, 2].iter().gt([1].iter()), true);
+    /// assert_eq!([1, 2].iter().gt([1, 2].iter()), false);
     /// ```
     #[stable(feature = "iter_order", since = "1.5.0")]
     fn gt<I>(self, other: I) -> bool
@@ -3137,6 +3140,7 @@ pub trait Iterator {
     /// assert_eq!([1].iter().ge([1].iter()), true);
     /// assert_eq!([1].iter().ge([1, 2].iter()), false);
     /// assert_eq!([1, 2].iter().ge([1].iter()), true);
+    /// assert_eq!([1, 2].iter().ge([1, 2].iter()), true);
     /// ```
     #[stable(feature = "iter_order", since = "1.5.0")]
     fn ge<I>(self, other: I) -> bool