TerminateProcess on a process that has not done initialization keeps a zombie around indefinitely

Steps to reproduce:

• Create a process with CREATE_SUSPENDED so it won't call any initialization routines
• Call TerminateProcess on that process

I've added a test for this in kernel32_apitest:TerminateProcess that complains about the resulting zombie process: https://reactos.org/sites/all/modules/reactos/testman/detail.php?id=19273891&prev=0

My guess so far is that csrss is keeping a handle open to this process, but that's not yet verified.