Save away the locations at the site we hit and iterate over that collection.  Otherwise the action of one location
could delete the other locations, and that would leave us iterating over a reduced size collection and crash.

<rdar://problem/13592544>


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@179332 91177308-0d34-0410-b5e6-96231b3b80d8