[DwarfDump] -debug-line=offset applies to .dwo too.

llvm-svn: 318856
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index cd7a81f..5893f22 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -379,9 +379,11 @@
       if (It != LineToUnit.end())
         U = It->second;
       DWARFDebugLine::LineTable LineTable;
+      unsigned OldOffset = Offset;
       if (!LineTable.Prologue.parse(LineData, &Offset, U))
         break;
-      LineTable.dump(OS);
+      if (!DumpOffset || OldOffset == *DumpOffset)
+        LineTable.dump(OS);
     }
   }