Update OpenBSD glob implementation for Windows (#16948)

We're considering making this used as a glob implementation on POSIX as
well, but first, we should rebase it from the latest version of OpenBSD.

This also adds a new internal header (charclass.h) for glob.

See conversation in GH-15564.

Co-authored-by: Christoph M. Becker <cmbecker69@gmx.de>

Author: NattyNarwhal

win32/charclass.h

@@ -0,0 +1,29 @@
+/*
+ * Public domain, 2008, Todd C. Miller <millert@openbsd.org>
+ *
+ * $OpenBSD: charclass.h,v 1.3 2020/10/13 04:42:28 guenther Exp $
+ */
+
+/*
+ * POSIX character class support for fnmatch() and glob().
+ */
+static const struct cclass {
+	const char *name;
+	int (*isctype)(int);
+} cclasses[] = {
+	{ "alnum",	isalnum },
+	{ "alpha",	isalpha },
+	{ "blank",	isblank },
+	{ "cntrl",	iscntrl },
+	{ "digit",	isdigit },
+	{ "graph",	isgraph },
+	{ "lower",	islower },
+	{ "print",	isprint },
+	{ "punct",	ispunct },
+	{ "space",	isspace },
+	{ "upper",	isupper },
+	{ "xdigit",	isxdigit },
+	{ NULL,		NULL }
+};
+
+#define NCCLASSES	(sizeof(cclasses) / sizeof(cclasses[0]) - 1)