Create a stub for DWARF parser unittests

Moves one DWARF-specific header to include/llvm/DebugInfo from lib/.
Add a short unittest for r179095.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179678 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/DebugInfo/DWARFCompileUnit.cpp b/lib/DebugInfo/DWARFCompileUnit.cpp
index 1f2b40f..4f0eed4 100644
--- a/lib/DebugInfo/DWARFCompileUnit.cpp
+++ b/lib/DebugInfo/DWARFCompileUnit.cpp
@@ -9,7 +9,7 @@
 
 #include "DWARFCompileUnit.h"
 #include "DWARFContext.h"
-#include "DWARFFormValue.h"
+#include "llvm/DebugInfo/DWARFFormValue.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/raw_ostream.h"