Summary: This option was added downstream in swift-lldb. This upstreams this option as it seems useful and also adds the missing tests.
Reviewers: #lldb, kwk, labath
Reviewed By: kwk, labath
Subscribers: labath, kwk, abidh, JDevlieghere, lldb-commits
Tags: #lldb, #upstreaming_lldb_s_downstream_patches
Differential Revision: https://reviews.llvm.org/D69944
