Test using lldb on linux

[springmeyer]

Refs http://clang.llvm.org/docs/UsersManual.html#controlling-debugger-tuning

[springmeyer]

non-actionable, was able to package latest gdb in mason (#12), and lldb (both 3.8.x and 4.x) seems to crash on linux.

[springmeyer]

re-opening. lldb 3.9.1 may be fixed now on linux (https://llvm.org/bugs/show_bug.cgi?id=26322)