From Hallvard B Furuseth <h.b.furuseth@usit.uio.no>.
/* Whether to use ISO C Amendment 1 wide char functions.
Those should not be used for Emacs since it uses its own. */
+#if defined _LIBC
+#define WIDE_CHAR_SUPPORT 1
+#else
#define WIDE_CHAR_SUPPORT \
- (defined _LIBC || HAVE_WCTYPE_H && HAVE_WCHAR_H && HAVE_BTOWC && !emacs)
+ (HAVE_WCTYPE_H && HAVE_WCHAR_H && HAVE_BTOWC && !emacs)
+#endif
/* For platform which support the ISO C amendement 1 functionality we
support user defined character classes. */