Fix Rendezvous breakpoint to only be set once, resolve addr in BreakpointLocationList::FindByAddress

Differential Revision: http://llvm-reviews.chandlerc.com/D1145

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@186458 91177308-0d34-0410-b5e6-96231b3b80d8