qtest: add qtest_pid()

Used in the following test on win32, to share sockets with the QEMU
process.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20230606115658.677673-7-marcandre.lureau@redhat.com>
2 files changed