Test 3.t exercises io_submit() with invalid addresses,
and one test attempted to pass in "-1" as an invalid
pointer. But gcc-11 realizes you cannot take an offset
from an invalid pointer, making it impossible to
compile or run this test:

sh# make CC=gcc-11 partcheck
make[1]: Entering directory '/alt/public_software/libaio/src'
make[1]: Nothing to be done for 'all'.
make[1]: Leaving directory '/alt/public_software/libaio/src'
make[1]: Entering directory '/alt/public_software/libaio/harness'
gcc-11 -Wall -Werror -I../src -g -O2 -DTEST_NAME=\"cases/2.t\" -o cases/2.p main.c ../src/libaio.a -lpthread
gcc-11 -Wall -Werror -I../src -g -O2 -DTEST_NAME=\"cases/3.t\" -o cases/3.p main.c ../src/libaio.a -lpthread
In file included from main.c:24:
cases/3.t: In function ‘test_main’:
cases/3.t:18:19: error: ‘attempt_io_submit’ accessing 8 bytes in a region of size 0 [-Werror=stringop-overflow=]
18 | status |= attempt_io_submit( io_ctx, 1, (void )-1, -EFAULT);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cases/3.t:18:19: note: referencing argument 3 of type ‘struct iocb ’
In file included from cases/3.t:5,
from main.c:24:
cases/aio_setup.h:15:5: note: in a call to function ‘attempt_io_submit’
15 | int attempt_io_submit(io_context_t ctx, long nr, struct iocb ios[], int expect)
| ^~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[1]: *** [Makefile:19: cases/3.p] Error 1
make[1]: Leaving directory '/alt/public_software/libaio/harness'
make: *** [Makefile:23: partcheck] Error 2

The fix is to tell gcc to relax it's stringop overflow
testing for this one test.

Changes since v1:
* First version just skipped the test in question

Signed-off-by: Lee Duncan leeman.duncan@gmail.com