* libio/wfileops.c (_IO_wfile_underflow): Remove incorrect test
for possible conversion using __codecvt_do_in.
* libio/Makefile (tests): Add tst-fgetws.
* libio/tst-fgetws.c: New file.
* libio/iofgetws.c: Use _IO_ferror_unlocked macros instead of
coding the test here.
