FcUtf16ToUcs4 - convert UTF-16 to UCS4
#include <fontconfig/fontconfig.h>
int FcUtf16ToUcs4 (FcChar8 *src, FcEndian endian, FcChar32 *dst, int len);
Converts the next Unicode char from src into dst and returns the
number of bytes containing the char. src must be at least len
bytes long. Bytes of src are combined into 16-bit units according to
endian.