Changing DebugInfoFinder to iterate over all the compile units.
Solves http://llvm.org/bugs/show_bug.cgi?id=17507

Committed on behalf of alon.mishne@intel.com

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192879 91177308-0d34-0410-b5e6-96231b3b80d8