SB API clients can describe the failure message in a more natural
way for their UI, this doesn't add information for them.
Differential Revision: https://reviews.llvm.org/D74585
<rdar://problem/49953304>
This can e.g. happen if the debugged executable exits before the initial
stop, e.g. if it fails to load dependent DLLs.
Add a virtual destructor to ProcessDebugger and let it clean up the
session, and make ProcessWindows::OnExitProcess call
ProcessDebugger::OnExitProcess for shared parts.
Fix suggestion by Adrian McCarthy.
Differential Revision: https://reviews.llvm.org/D69503
