git: 2df58f190731 - main - Apply libc++ fix for compiling <type_traits> with gcc 13

The branch main has been updated by dim:

URL: https://cgit.FreeBSD.org/src/commit/?id=2df58f190731634be67e90b7c453dee587b4ea27

commit 2df58f190731634be67e90b7c453dee587b4ea27
Author:     Dimitry Andric <dim@FreeBSD.org>
AuthorDate: 2023-05-05 16:19:40 +0000
Commit:     Dimitry Andric <dim@FreeBSD.org>
CommitDate: 2023-05-05 16:19:40 +0000

    Apply libc++ fix for compiling <type_traits> with gcc 13
    
    Merge commit 484e64f7e7b2 from llvm-project (by Roland McGrath):
    
      [libc++] Use __is_convertible built-in when available
    
      https://github.com/llvm/llvm-project/issues/62396 reports that
      GCC 13 barfs on parsing <type_traits> because of the declarations
      of `struct __is_convertible`.  In GCC 13, `__is_convertible` is a
      built-in, but `__is_convertible_to` is not.  Clang has both, so
      using either should be fine.
    
      Reviewed By: #libc, philnik
    
      Differential Revision: https://reviews.llvm.org/D149313
    
    Reported by:    Mark Millard <marklmi@yahoo.com>
    MFC after:      3 days
---
 .../llvm-project/libcxx/include/__type_traits/is_convertible.h   | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/contrib/llvm-project/libcxx/include/__type_traits/is_convertible.h b/contrib/llvm-project/libcxx/include/__type_traits/is_convertible.h
index 7e49cd4e6a31..7ce3c38b76de 100644
--- a/contrib/llvm-project/libcxx/include/__type_traits/is_convertible.h
+++ b/contrib/llvm-project/libcxx/include/__type_traits/is_convertible.h
@@ -24,11 +24,18 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if __has_builtin(__is_convertible_to) && !defined(_LIBCPP_USE_IS_CONVERTIBLE_FALLBACK)
+#if __has_builtin(__is_convertible) && !defined(_LIBCPP_USE_IS_CONVERTIBLE_FALLBACK)
+
+template <class _T1, class _T2>
+struct _LIBCPP_TEMPLATE_VIS is_convertible : public integral_constant<bool, __is_convertible(_T1, _T2)> {};
+
+#elif __has_builtin(__is_convertible_to) && !defined(_LIBCPP_USE_IS_CONVERTIBLE_FALLBACK)
 
 template <class _T1, class _T2> struct _LIBCPP_TEMPLATE_VIS is_convertible
     : public integral_constant<bool, __is_convertible_to(_T1, _T2)> {};
 
+// TODO: Remove this fallback when GCC < 13 support is no longer required.
+// GCC 13 has the __is_convertible built-in.
 #else  // __has_builtin(__is_convertible_to) && !defined(_LIBCPP_USE_IS_CONVERTIBLE_FALLBACK)
 
 namespace __is_convertible_imp