When using LLDB, the first and last call should be
SBDebugger::Initialize and SBDebugger::Terminate respectively.
While we're resilient against mistakes, I'm adding an assert (#185162)
to debug builds to catch those mistakes in-tree as they have the
potential to leak resources. The assert was tripped by Dexter.
This PR adds the missing calls to SBDebugger::{Initialize,Terminate},
and while I was at it, I also added a missing call to
SBDebugger::Destroy. With that, the Dexter tests pass locally with the
assert enabled.
d6b32e7dfe