Remove empty non-virtual destructors or mark them =default when non-public

These add no value but can make a class non-trivially copyable. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234688 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/RegionInfo.h

@@ -820,8 +820,6 @@ public:
   inline RegionNode(Region *Parent, BasicBlock *Entry, bool isSubRegion = false)
       : RegionNodeBase<RegionTraits<Function>>(Parent, Entry, isSubRegion) {}
 
-  ~RegionNode() {}
-
   bool operator==(const Region &RN) const {
     return this == reinterpret_cast<const RegionNode *>(&RN);
   }