Found one more place where the OkayToDiscard needs to be consulted.
Also changed the defaults for SBThread::Step* to not delete extant plans.
Also added some test cases to test more complex stepping scenarios.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@156667 91177308-0d34-0410-b5e6-96231b3b80d8
9 files changed