Add iswpunct(3) breakage workaround for Android

On Android 14.0 with Termux 0.118.0, one regression test failure
remains, in src/cmd/ksh93/tests/sh_match.sh: the '$' character does
not match the [[:punct:]] character class, which is incorrect.

This character class queries the system's iswpunct(3) function via
src/lib/libast/regex/regclass.c, even for plain single-byte ASCII
characters; it should be equivalent to ispunct(3) in that case.

Turns out iswpunct(3) is simply broken on Android. Nine of the
expected ASCII characters are not recognised, whereas ispunct(3) is
fine. A test program shows:

    ispunct('!')==16; iswpunct('!')==1
    ispunct('"')==16; iswpunct('"')==1
    ispunct('#')==16; iswpunct('#')==1
    ispunct('$')==16; iswpunct('$')==0
    ispunct('%')==16; iswpunct('%')==1
    ispunct('&')==16; iswpunct('&')==1
    ispunct(''')==16; iswpunct(''')==1
    ispunct('(')==16; iswpunct('(')==1
    ispunct(')')==16; iswpunct(')')==1
    ispunct('*')==16; iswpunct('*')==1
    ispunct('+')==16; iswpunct('+')==0
    ispunct(',')==16; iswpunct(',')==1
    ispunct('-')==16; iswpunct('-')==1
    ispunct('.')==16; iswpunct('.')==1
    ispunct('/')==16; iswpunct('/')==1
    ispunct(':')==16; iswpunct(':')==1
    ispunct(';')==16; iswpunct(';')==1
    ispunct('<')==16; iswpunct('<')==0
    ispunct('=')==16; iswpunct('=')==0
    ispunct('>')==16; iswpunct('>')==0
    ispunct('?')==16; iswpunct('?')==1
    ispunct('@')==16; iswpunct('@')==1
    ispunct('[')==16; iswpunct('[')==1
    ispunct('\')==16; iswpunct('\')==1
    ispunct(']')==16; iswpunct(']')==1
    ispunct('^')==16; iswpunct('^')==0
    ispunct('_')==16; iswpunct('_')==1
    ispunct('`')==16; iswpunct('`')==0
    ispunct('{')==16; iswpunct('{')==1
    ispunct('|')==16; iswpunct('|')==0
    ispunct('}')==16; iswpunct('}')==1
    ispunct('~')==16; iswpunct('~')==0

It's broken for multibyte UTF-8 characters as well; at least £ and
€ are not recognised as punctuation. But there's nothing we can
realistically do about that. But we can at least fix the ASCII
characters as those are important for portability.

src/cmd/ksh93/tests/sh_match.sh

@@ -78,7 +78,10 @@
 [[ $'\cg' =~ [[:cntrl:]] ]] || err_exit 'pattern [[:cntrl:]] broken'
 [[ \$ =~ [[:graph:]] ]] || err_exit 'pattern [[:graph:]] broken'
 [[ ' ' =~ [[:graph:]] ]] && err_exit 'pattern [[:graph:]] broken'
-[[ \$ =~ [[:punct:]] ]] || err_exit 'pattern [[:punct:]] broken'
+for c in '!' '"' '#' '$' '%' '&' \' '(' ')' '*' '+' ',' '-' '.' '/' ':' ';' \
+		'<' '=' '>' '?' '@' '[' '\\' ']' '^' '_' '`' '{' '|' '}' '~'
+do	[[ $c =~ [[:punct:]] ]] || err_exit "pattern [[:punct:]] broken for $c"
+done
 [[ / =~ [[:punct:]] ]] || err_exit 'pattern [[:punct:]] broken'
 [[ ' ' =~ [[:punct:]] ]] && err_exit 'pattern [[:punct:]] broken'
 [[ x =~ [[:punct:]] ]] && err_exit 'pattern [[:punct:]] broken'

src/lib/libast/features/wchar

@@ -56,6 +56,22 @@ if	hdr - wctype wchar.h
 	endif
 endif
 
+tst	iswpunct_broken note{ is iswpunct(3) broken }end execute{
+	/* on Android 14.0, it is: it does not recognise some of the ASCII characters. ispunct(3) is fine */
+	#include <ctype.h>
+	#include <wctype.h>
+	int main(void)
+	{
+		char c[] = { '!', '"', '#', '$', '%', '&', '\'', '(', ')', '*', '+', ',', '-', '.', '/', ':', ';',
+				'<', '=', '>', '?', '@', '[', '\\', ']', '^', '_', '`', '{', '|', '}', '~', '\0' };
+		int i;
+		for (i = 0; c[i]; i++)
+			if (ispunct(c[i]) && !iswpunct(c[i]))
+				return 0;
+		return 1;
+	}
+}end
+
 run{
 cat <<!
 	#ifndef WEOF

src/lib/libast/regex/regclass.c

@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1985-2011 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -71,7 +71,14 @@ static int Notdigit(int c) { return !iswdigit(c); }
 static int  Isgraph(int c) { return  iswgraph(c); }
 static int  Islower(int c) { return  iswlower(c); }
 static int  Isprint(int c) { return  iswprint(c); }
-static int  Ispunct(int c) { return  iswpunct(c); }
+static int  Ispunct(int c)
+{
+#if _iswpunct_broken && CC_NATIVE == CC_ASCII
+	if (c < 128)
+		return ispunct(c);
+#endif
+	return iswpunct(c);
+}
 static int  Isspace(int c) { return  iswspace(c); }
 static int Notspace(int c) { return !iswspace(c); }
 static int  Isupper(int c) { return  iswupper(c); }