Remove lldb-repro which was used to run the test suite against a
reproducer. The corresponding functionality has been removed from LLDB
so there's no need for the tool anymore.
The reproducers currently only shadow the command interpreter. It would
be possible to make it work for the Lua interpreter which uses the
IOHandlerEditline under the hood, but the Python one runs a REPL in
Python itself so there's no (straightforward) way to shadow that.
Given that we already capture any API calls, this isn't super high on my
list of priorities.
