Merge "Do not typedef char16_t if it is a keyword."

extern "C" {

#endif

#if __STDC_VERSION__ < 201112L && __cplusplus < 201103L

  typedef uint16_t char16_t;

#endif

  // otherwise char16_t is a keyword with the right semantics

extern char * strndup16to8 (const char16_t* s, size_t n);

extern size_t strnlen16to8 (const char16_t* s, size_t n);