New utility function: dupwcs.

Just like dupstr, but for wchar_t strings.

utils/dupwcs.c

@@ -0,0 +1,19 @@
+/*
+ * Allocate a duplicate of a NUL-terminated wchar_t string.
+ */
+
+#include <wchar.h>
+
+#include "defs.h"
+#include "misc.h"
+
+wchar_t *dupwcs(const wchar_t *s)
+{
+    wchar_t *p = NULL;
+    if (s) {
+        int len = wcslen(s);
+        p = snewn(len + 1, wchar_t);
+        wcscpy(p, s);
+    }
+    return p;
+}