Move m_destroy_in_process to Process (from ProcessKDP) since it is generally useful,
and use it to keep from doing the OS Plugin UpdateThreadList while destroying, since
if that does anything that requires the API lock it may deadlock against whoever is
running the Process::Destroy.

<rdar://problem/13308627>


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@176375 91177308-0d34-0410-b5e6-96231b3b80d8