standards/58595: C11: no uchar.h

[Thomas Klausner <wiz%NetBSD.org@localhost>]

>Number:         58595
>Category:       standards
>Synopsis:       C11: no uchar.h
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    standards-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Aug 14 10:20:00 +0000 2024
>Originator:     Thomas Klausner
>Release:        NetBSD 10.99.11
>Organization:

>Environment:
	
	
Architecture: x86_64
Machine: amd64
>Description:
NetBSD does not provide a uchar.h header.

I didn't find a proper link for this, but
https://pubs.opengroup.org/onlinepubs/9799919799.2024edition/basedefs/uchar.h.html
says it's "aligned" with the "ISO C standard" and
https://en.cppreference.com/w/c/header mentions C11.
>How-To-Repeat:
Compile a file including:

#include <uchar.h>

>Fix:
Provide uchar.h

According to opengroup, this needs to provide:
mbstate_t
size_t
char16_t
char32_t
size_t  c16rtomb(char *restrict, char16_t, mbstate_t *restrict);
size_t  c32rtomb(char *restrict, char32_t, mbstate_t *restrict);
size_t  mbrtoc16(char16_t *restrict, const char *restrict, size_t, mbstate_t *restrict);
size_t  mbrtoc32(char32_t *restrict, const char *restrict, size_t, mbstate_t *restrict);

and may make symbols visible from stddef.h, stdint.h, and wchar.h.

>Unformatted: