[MergeFunc] Delete unused FunctionNode::release()

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358742 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/MergeFunctions.cpp b/lib/Transforms/IPO/MergeFunctions.cpp
index 9b3bf85..08a6c4e 100644
--- a/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/lib/Transforms/IPO/MergeFunctions.cpp
@@ -189,8 +189,6 @@
   void replaceBy(Function *G) const {
     F = G;
   }
-
-  void release() { F = nullptr; }
 };
 
 /// MergeFunctions finds functions which will generate identical machine code,