[libc] Add is_member_pointer_v (#65631)

Implementation from
https://en.cppreference.com/w/cpp/types/is_member_pointer

Author: gchatelet

libc/src/__support/CPP/type_traits.h

@@ -30,6 +30,7 @@
 #include "src/__support/CPP/type_traits/is_function.h"
 #include "src/__support/CPP/type_traits/is_integral.h"
 #include "src/__support/CPP/type_traits/is_lvalue_reference.h"
+#include "src/__support/CPP/type_traits/is_member_pointer.h"
 #include "src/__support/CPP/type_traits/is_null_pointer.h"
 #include "src/__support/CPP/type_traits/is_pointer.h"
 #include "src/__support/CPP/type_traits/is_reference.h"

libc/src/__support/CPP/type_traits/is_member_pointer.h

@@ -0,0 +1,30 @@
+//===-- is_member_pointer type_traits ---------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_LIBC_SRC_SUPPORT_CPP_TYPE_TRAITS_IS_MEMBER_POINTER_H
+#define LLVM_LIBC_SRC_SUPPORT_CPP_TYPE_TRAITS_IS_MEMBER_POINTER_H
+
+#include "src/__support/CPP/type_traits/false_type.h"
+#include "src/__support/CPP/type_traits/remove_cv.h"
+#include "src/__support/CPP/type_traits/true_type.h"
+#include "src/__support/macros/attributes.h"
+
+namespace __llvm_libc::cpp {
+
+// is_member_pointer
+template <class T> struct is_member_pointer_helper : cpp::false_type {};
+template <class T, class U>
+struct is_member_pointer_helper<T U::*> : cpp::true_type {};
+template <class T>
+struct is_member_pointer : is_member_pointer_helper<cpp::remove_cv_t<T>> {};
+template <class T>
+LIBC_INLINE_VAR constexpr bool is_member_pointer_v =
+    is_member_pointer<T>::value;
+
+} // namespace __llvm_libc::cpp
+
+#endif // LLVM_LIBC_SRC_SUPPORT_CPP_TYPE_TRAITS_IS_MEMBER_POINTER_H

utils/bazel/llvm-project-overlay/libc/BUILD.bazel

@@ -307,6 +307,7 @@ libc_support_library(
         "src/__support/CPP/type_traits/is_function.h",
         "src/__support/CPP/type_traits/is_integral.h",
         "src/__support/CPP/type_traits/is_lvalue_reference.h",
+        "src/__support/CPP/type_traits/is_member_pointer.h",
         "src/__support/CPP/type_traits/is_null_pointer.h",
         "src/__support/CPP/type_traits/is_pointer.h",
         "src/__support/CPP/type_traits/is_reference.h",