include: map EILSEQ error code

PR-URL: https://github.com/libuv/libuv/pull/2440
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

include/uv.h

@@ -143,6 +143,7 @@ extern "C" {
   XX(EREMOTEIO, "remote I/O error")                                           \
   XX(ENOTTY, "inappropriate ioctl for device")                                \
   XX(EFTYPE, "inappropriate file type or format")                             \
+  XX(EILSEQ, "illegal byte sequence")                                         \
 
 #define UV_HANDLE_TYPE_MAP(XX)                                                \
   XX(ASYNC, async)                                                            \

include/uv/errno.h

@@ -439,5 +439,10 @@
 # define UV__EFTYPE (-4028)
 #endif
 
+#if defined(EILSEQ) && !defined(_WIN32)
+# define UV__EILSEQ UV__ERR(EILSEQ)
+#else
+# define UV__EILSEQ (-4027)
+#endif
 
 #endif /* UV_ERRNO_H_ */