Mark class as hidden.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71850 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DIE.h b/lib/CodeGen/AsmPrinter/DIE.h
index 7b43466..8c0a826 100644
--- a/lib/CodeGen/AsmPrinter/DIE.h
+++ b/lib/CodeGen/AsmPrinter/DIE.h
@@ -503,7 +503,7 @@
   //===--------------------------------------------------------------------===//
   /// DIEBlock - A block of values.  Primarily used for location expressions.
   //
-  class DIEBlock : public DIEValue, public DIE {
+  class VISIBILITY_HIDDEN DIEBlock : public DIEValue, public DIE {
     unsigned Size;                // Size in bytes excluding size header.
   public:
     DIEBlock()