git: 66129def7bda - main - sys/_types.h: recognise char8_t as a builtin type in C++20

The branch main has been updated by fuz:

URL: https://cgit.FreeBSD.org/src/commit/?id=66129def7bdaf8a0447aba55e736d27687204555

commit 66129def7bdaf8a0447aba55e736d27687204555
Author:     Robert Clausecker <fuz@FreeBSD.org>
AuthorDate: 2025-12-07 23:49:05 +0000
Commit:     Robert Clausecker <fuz@FreeBSD.org>
CommitDate: 2025-12-09 13:16:31 +0000

    sys/_types.h: recognise char8_t as a builtin type in C++20
    
    Unlike in C23 where it's a typedef, char8_t is a built in type in
    C++20.  Recognise it as such.
    
    PR:             291449
    Reported by:    Tomoaki AOKI <junchoon@dec.sakura.ne.jp>
    Approved by:    markj (mentor)
    Reviewed by:    imp
    Fixes:          f0e541118c374869a8226eaa1320bb6eda248a20
    MFC after:      1 week
    Differential Revision:  https://reviews.freebsd.org/D54124
---
 sys/sys/_types.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sys/sys/_types.h b/sys/sys/_types.h
index 4e217704ceb6..2e622090e81d 100644
--- a/sys/sys/_types.h
+++ b/sys/sys/_types.h
@@ -207,6 +207,10 @@ typedef	__uint_least32_t __char32_t;
 #define	_CHAR16_T_DECLARED
 #define	_CHAR32_T_DECLARED
 #endif
+/* and so is char8_t in C++20 */
+#if defined(__cplusplus) && __cplusplus >= 202002L
+#define _CHAR8_T_DECLARED
+#endif
 
 typedef struct {
 	long long __max_align1