Unweaken vtables as per http://llvm.org/docs/CodingStandards.html#ll_virtual_anch

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146960 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/Spiller.h b/lib/CodeGen/Spiller.h
index 41f1727..b7d5bea 100644
--- a/lib/CodeGen/Spiller.h
+++ b/lib/CodeGen/Spiller.h
@@ -22,6 +22,7 @@
   /// Implementations are utility classes which insert spill or remat code on
   /// demand.
   class Spiller {
+    virtual void anchor();
   public:
     virtual ~Spiller() = 0;