Merge DenseMapKeyInfo & DenseMapValueInfo into DenseMapInfo

Add a new DenseMapInfo::isEqual method to allow clients to redefine
the equality predicate used when probing the hash table.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42042 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/DwarfWriter.cpp

@@ -2942,6 +2942,7 @@ private:
     static inline unsigned getEmptyKey() { return -1U; }
     static inline unsigned getTombstoneKey() { return -2U; }
     static unsigned getHashValue(const unsigned &Key) { return Key; }
+    static bool isEqual(unsigned LHS, unsigned RHS) { return LHS == RHS; }
     static bool isPod() { return true; }
   };