[llvm] [ADT] Relax iterator constraints on all_equal (PR #106400)

[Jakub Kuderski via llvm-commits]

================
@@ -831,6 +832,26 @@ TEST(STLExtrasTest, AllEqual) {
   EXPECT_FALSE(all_equal(V));
 }
 
+// Test to verify that all_equal works with a container that does not 
+// model the random access iterator concept.
+TEST(STLExtrasTest, AllEqualNonRandomAccess) {
+  std::list<int> V;
+  static_assert(!std::is_convertible<std::iterator_traits<decltype(V)::iterator>::iterator_category,
+                                     std::random_access_iterator_tag >::value);
----------------
kuhar wrote:

```suggestion
  static_assert(!std::is_convertible_v<std::iterator_traits<decltype(V)::iterator>::iterator_category,
                                     std::random_access_iterator_tag >);
```

https://github.com/llvm/llvm-project/pull/106400