[libc++][ranges] Add ranges::min_max_result

Reviewed By: Quuxplusone, #libc

Spies: libcxx-commits, mgorny

Differential Revision: https://reviews.llvm.org/D119751

NOKEYCHECK=True
GitOrigin-RevId: 807766be3a89e2d4c9c935db2edd8c665f4d7567
diff --git a/include/algorithm b/include/algorithm
index b35ad67..9149995 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -20,17 +20,20 @@
 
 namespace ranges {
   template <class I, class F>
-    struct in_fun_result; // since C++20
+    struct in_fun_result;     // since C++20
 
   template <class I1, class I2>
-    struct in_in_result;     // since C++20
+    struct in_in_result;      // since C++20
 
   template <class I1, class I2, class O>
-    struct in_in_out_result; // since C++20
+    struct in_in_out_result;  // since C++20
 
   template <class I, class O1, class O2>
     struct in_out_out_result; // since C++20
 
+  template <class I1, class I2>
+    struct min_max_result;    // since C++20
+
   template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
     indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>             // since C++20
   constexpr I min_element(I first, S last, Comp comp = {}, Proj proj = {});
@@ -738,6 +741,7 @@
 #include <__algorithm/merge.h>
 #include <__algorithm/min.h>
 #include <__algorithm/min_element.h>
+#include <__algorithm/min_max_result.h>
 #include <__algorithm/minmax.h>
 #include <__algorithm/minmax_element.h>
 #include <__algorithm/mismatch.h>