We are doing spurious name lookups when running expressions in objective C methods.

<rdar://problem/15797390>

This new test case will detect this and make sure we don't regress on global name lookups that search all DWARF for everything when we don't need to.



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@198982 91177308-0d34-0410-b5e6-96231b3b80d8