diff --git a/llvm/include/llvm/ADT/DenseMapInfo.h b/llvm/include/llvm/ADT/DenseMapInfo.h
--- a/llvm/include/llvm/ADT/DenseMapInfo.h
+++ b/llvm/include/llvm/ADT/DenseMapInfo.h
@@ -13,7 +13,6 @@
 #ifndef LLVM_ADT_DENSEMAPINFO_H
 #define LLVM_ADT_DENSEMAPINFO_H
 
-#include "llvm/ADT/Hashing.h"
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
@@ -283,13 +282,6 @@
   }
 };
 
-template <> struct DenseMapInfo<hash_code> {
-  static inline hash_code getEmptyKey() { return hash_code(-1); }
-  static inline hash_code getTombstoneKey() { return hash_code(-2); }
-  static unsigned getHashValue(hash_code val) { return val; }
-  static bool isEqual(hash_code LHS, hash_code RHS) { return LHS == RHS; }
-};
-
 } // end namespace llvm
 
 #endif // LLVM_ADT_DENSEMAPINFO_H
diff --git a/llvm/include/llvm/ADT/Hashing.h b/llvm/include/llvm/ADT/Hashing.h
--- a/llvm/include/llvm/ADT/Hashing.h
+++ b/llvm/include/llvm/ADT/Hashing.h
@@ -56,6 +56,7 @@
 #include <utility>
 
 namespace llvm {
+template <typename T> struct DenseMapInfo;
 
 /// An opaque object representing a hash code.
 ///
@@ -677,6 +678,13 @@
   return hash_combine_range(arg.begin(), arg.end());
 }
 
+template <> struct DenseMapInfo<hash_code> {
+  static inline hash_code getEmptyKey() { return hash_code(-1); }
+  static inline hash_code getTombstoneKey() { return hash_code(-2); }
+  static unsigned getHashValue(hash_code val) { return val; }
+  static bool isEqual(hash_code LHS, hash_code RHS) { return LHS == RHS; }
+};
+
 } // namespace llvm
 
 #endif