SBQueue::GetNumPendingItems() should not force a fetch of the pending
items; the backing Queue object has the number of pending items
already cached.  Also, add SBQueue::GetNumRunningItems() to provide
that information.
<rdar://problem/16272016> 



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@203420 91177308-0d34-0410-b5e6-96231b3b80d8