When target module add/SBTarget::AddModule()'ing, if an architecture isn't specifically
requested, use the Target's architecture to pick the correct slice of a universal file.
<rdar://problem/14813869> 


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@190550 91177308-0d34-0410-b5e6-96231b3b80d8