DebugInfo: Gut DIScope, DIEnumerator and DISubrange

The only class the still has API left is `DIDescriptor` itself.

llvm-svn: 235067
diff --git a/llvm/lib/CodeGen/LiveDebugVariables.cpp b/llvm/lib/CodeGen/LiveDebugVariables.cpp
index a07a7c9..52532b14 100644
--- a/llvm/lib/CodeGen/LiveDebugVariables.cpp
+++ b/llvm/lib/CodeGen/LiveDebugVariables.cpp
@@ -362,9 +362,9 @@
   if (!DL)
     return;
 
-  DIScope Scope = cast<MDScope>(DL.getScope());
+  auto *Scope = cast<MDScope>(DL.getScope());
   // Omit the directory, because it's likely to be long and uninteresting.
-  CommentOS << Scope.getFilename();
+  CommentOS << Scope->getFilename();
   CommentOS << ':' << DL.getLine();
   if (DL.getCol() != 0)
     CommentOS << ':' << DL.getCol();