* sysdeps/pthread/aio_cancel.c (aio_cancel): Add check for invalid
file descriptor.
* sysdeps/pthread/aio_fsync.c (aio_fsync): Add check for invalid fd;
add check for fd not open for writing.
* sysdeps/pthread/aio_suspend.c (aio_suspend): Add check for
completed element(s) and do not suspend thread if so. Patch
heavily modified by drepper.
* rt/tst-aio7.c: New file. Regression test for problems which the
above three changes fix.
* rt/Makefile (tests): Add tst-aio7.