diff --git a/llvm/include/llvm/ADT/GenericUniformityImpl.h b/llvm/include/llvm/ADT/GenericUniformityImpl.h
--- a/llvm/include/llvm/ADT/GenericUniformityImpl.h
+++ b/llvm/include/llvm/ADT/GenericUniformityImpl.h
@@ -468,8 +468,9 @@
 };
 
 template <typename ContextT>
-void GenericUniformityInfo<ContextT>::ImplDeleter::operator()(
-    GenericUniformityAnalysisImpl<ContextT> *Impl) {
+template <typename DelT>
+void GenericUniformityInfo<ContextT>::ImplDeleter<DelT>::operator()(
+    DelT *Impl) {
   delete Impl;
 }
 
diff --git a/llvm/include/llvm/ADT/GenericUniformityInfo.h b/llvm/include/llvm/ADT/GenericUniformityInfo.h
--- a/llvm/include/llvm/ADT/GenericUniformityInfo.h
+++ b/llvm/include/llvm/ADT/GenericUniformityInfo.h
@@ -63,12 +63,16 @@
 
 private:
   using ImplT = GenericUniformityAnalysisImpl<ContextT>;
-  struct ImplDeleter {
-    void operator()(GenericUniformityAnalysisImpl<ContextT> *Impl);
+  // Ugly hack around the fact that recent (> 15.0) clang will run into an
+  // is_invocable() check in some GNU libc++'s unique_ptr implementation
+  // and reject this deleter if you just make it callable with an ImplT *,
+  // whether or not the type of ImplT is spelled out.
+  template <typename DelT = ImplT> struct ImplDeleter {
+    void operator()(DelT *Impl);
   };
 
   FunctionT *F;
-  std::unique_ptr<ImplT, ImplDeleter> DA;
+  std::unique_ptr<ImplT, ImplDeleter<ImplT>> DA;
 
   GenericUniformityInfo(const GenericUniformityInfo &) = delete;
   GenericUniformityInfo &operator=(const GenericUniformityInfo &) = delete;