DWARF: Put all the pieces we have together and provide a single accessor to DIContext that provides line information when given an address.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139836 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/DebugInfo/DWARFDebugLine.cpp b/lib/DebugInfo/DWARFDebugLine.cpp
index 941d881..94fff65 100644
--- a/lib/DebugInfo/DWARFDebugLine.cpp
+++ b/lib/DebugInfo/DWARFDebugLine.cpp
@@ -122,7 +122,9 @@
     State state;
     if (!parseStatementTable(debug_line_data, &offset, state))
       return 0;
-    pos->second = state;
+    // FIXME: double lookup.
+    LineTableMap[offset] = state;
+    return &LineTableMap[offset];
   }
   return &pos->second;
 }