Update libc++ generated files, and add __assertion_handler.

Author: DimitryAndric

lib/libc++/Makefile

@@ -248,6 +248,10 @@ STD_HEADERS+=	wctype.h
 STD+=		${HDRDIR}/${hdr}
 .endfor
 
+# Special case for __assertion_handler, which as of libc++ 18.0.0 is generated
+# by CMake.
+STD+=		${.CURDIR}/__assertion_handler
+
 # Special case for __config_site, which as of libc++ 12.0.0 is generated by
 # CMake, and as of 13.0.0 installed side-by-side with__config.
 STD+=		${.CURDIR}/__config_site

lib/libc++/__assertion_handler

@@ -0,0 +1,31 @@
+// -*- 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 _LIBCPP___ASSERTION_HANDLER
+#define _LIBCPP___ASSERTION_HANDLER
+
+#include <__config>
+#include <__verbose_abort>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_DEBUG
+
+#  define _LIBCPP_ASSERTION_HANDLER(message) _LIBCPP_VERBOSE_ABORT("%s", message)
+
+#else
+
+// TODO(hardening): use `__builtin_verbose_trap(message)` once that becomes available.
+#  define _LIBCPP_ASSERTION_HANDLER(message) ((void)message, __builtin_trap())
+
+#endif // _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_DEBUG
+
+#endif // _LIBCPP___ASSERTION_HANDLER

lib/libc++/__config_site

@@ -27,7 +27,7 @@
 /* #undef _LIBCPP_HAS_NO_RANDOM_DEVICE */
 /* #undef _LIBCPP_HAS_NO_LOCALIZATION */
 /* #undef _LIBCPP_HAS_NO_WIDE_CHARACTERS */
-#define _LIBCPP_HAS_NO_STD_MODULES
+/* #undef _LIBCPP_HAS_NO_STD_MODULES */
 #define _LIBCPP_HAS_NO_TIME_ZONE_DATABASE
 /* #undef _LIBCPP_INSTRUMENTED_WITH_ASAN */
 

lib/libc++/module.modulemap

@@ -1580,6 +1580,7 @@ module std_private_numeric_pstl_transform_reduce    [system] {
   export *
 }
 module std_private_numeric_reduce                   [system] { header "__numeric/reduce.h" }
+module std_private_numeric_saturation_arithmetic    [system] { header "__numeric/saturation_arithmetic.h" }
 module std_private_numeric_transform_exclusive_scan [system] { header "__numeric/transform_exclusive_scan.h" }
 module std_private_numeric_transform_inclusive_scan [system] { header "__numeric/transform_inclusive_scan.h" }
 module std_private_numeric_transform_reduce         [system] { header "__numeric/transform_reduce.h" }