Revert "[libc] Add reverse_iterator comparisons" (llvm#86186)

Reverts llvm#86147

Author: gchatelet

libc/src/__support/CPP/iterator.h

@@ -20,16 +20,13 @@ namespace cpp {
 template <typename T> struct iterator_traits;
 template <typename T> struct iterator_traits<T *> {
   using reference = T &;
-  using value_type = T;
 };
 
 template <typename Iter> class reverse_iterator {
   Iter current;
 
 public:
   using reference = typename iterator_traits<Iter>::reference;
-  using value_type = typename iterator_traits<Iter>::value_type;
-  using iterator_type = Iter;
 
   LIBC_INLINE reverse_iterator() : current() {}
   LIBC_INLINE constexpr explicit reverse_iterator(Iter it) : current(it) {}
@@ -41,38 +38,6 @@ template <typename Iter> class reverse_iterator {
   LIBC_INLINE constexpr explicit reverse_iterator(const Other &it)
       : current(it) {}
 
-  LIBC_INLINE friend constexpr bool operator==(const reverse_iterator &lhs,
-                                               const reverse_iterator &rhs) {
-    return lhs.base() == rhs.base();
-  }
-
-  LIBC_INLINE friend constexpr bool operator!=(const reverse_iterator &lhs,
-                                               const reverse_iterator &rhs) {
-    return lhs.base() != rhs.base();
-  }
-
-  LIBC_INLINE friend constexpr bool operator<(const reverse_iterator &lhs,
-                                              const reverse_iterator &rhs) {
-    return lhs.base() > rhs.base();
-  }
-
-  LIBC_INLINE friend constexpr bool operator<=(const reverse_iterator &lhs,
-                                               const reverse_iterator &rhs) {
-    return lhs.base() >= rhs.base();
-  }
-
-  LIBC_INLINE friend constexpr bool operator>(const reverse_iterator &lhs,
-                                              const reverse_iterator &rhs) {
-    return lhs.base() < rhs.base();
-  }
-
-  LIBC_INLINE friend constexpr bool operator>=(const reverse_iterator &lhs,
-                                               const reverse_iterator &rhs) {
-    return lhs.base() <= rhs.base();
-  }
-
-  LIBC_INLINE constexpr iterator_type base() const { current; }
-
   LIBC_INLINE constexpr reference operator*() const {
     Iter tmp = current;
     return *--tmp;