[IPO] Remove unused declaration RemoveUnusedGlobalValue

The corresponding function definition was removed by:

  commit 9071393c18e5264e3bbf3ca3f3584fa5f45be6c2
  Author: Jay Foad <jay.foad@amd.com>
  Date:   Thu Feb 17 14:17:36 2022 +0000

diff --git a/llvm/include/llvm/Transforms/IPO/GlobalDCE.h b/llvm/include/llvm/Transforms/IPO/GlobalDCE.h
index a24196e..1c01244 100644 (file)
--- a/llvm/include/llvm/Transforms/IPO/GlobalDCE.h
+++ b/llvm/include/llvm/Transforms/IPO/GlobalDCE.h
@@ -61,7 +61,6 @@ private:
   void UpdateGVDependencies(GlobalValue &GV);
   void MarkLive(GlobalValue &GV,
                 SmallVectorImpl<GlobalValue *> *Updates = nullptr);
-  bool RemoveUnusedGlobalValue(GlobalValue &GV);
 
   // Dead virtual function elimination.
   void AddVirtualFunctionDependencies(Module &M);