Add a gitlab-ci file

This is very convenient for people who store their QEMU git trees on
gitlab.com: Automatic CI pipelines are now run for each branch that is
pushed to the server. Since the runtime of the jobs is limited to 1h
we distribute the targets into multiple pipelines - this way the jobs
finish within 30 minutes.

Signed-off-by: Thomas Huth <thuth@redhat.com>
5 jobs for test in 31 minutes and 6 seconds
Status Name Job ID Coverage
  Test
failed build-clang #94080348

00:08:05

passed build-disabled #94080349

00:07:34

passed build-system1 #94080346

00:23:54

passed build-system2 #94080347

00:22:23

passed build-user #94080350

00:31:06

 
Name Stage Failure
failed
build-clang Test
migration/rdma.c:4015:41: note: initialize the variable 'rdma_return_path' to silence this warning
RDMAContext *rdma, *rdma_return_path;
^
= NULL
3 errors generated.
/builds/huth/qemu/rules.mak:69: recipe for target 'migration/rdma.o' failed
make: *** [migration/rdma.o] Error 1
make: *** Waiting for unfinished jobs....
ERROR: Job failed: exit code 1