Revert "Fix -Wnon-virtual-dtor warning introduced in r217982."

An alternative fix was already committed.

This reverts commit r217988.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217989 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Transforms/Utils/SimplifyLibCalls.h

@@ -36,9 +36,6 @@ private:
   const TargetLibraryInfo *TLI;
   bool UnsafeFPShrink;
 
-protected:
-  ~LibCallSimplifier() {}
-
 public:
   LibCallSimplifier(const DataLayout *TD, const TargetLibraryInfo *TLI,
                     bool UnsafeFPShrink);