[tests] Propagate runtime exit code in test_op_il_seq_point.sh (#11749)
We weren't checking whether the runtime returned a zero exit code which
means if the compilation failed we still reported success.
Now the exit code is propagated all the way up and we report an error
both to make and to the xml result file.
Since iltests.exe contains a test with expected invalid IL this would
now cause a failure. The easiest fix is to just move that test from
mono/mini to mono/tests since all other tests are fine.
Fixes https://github.com/mono/mono/issues/11091