[clangd] llvm::integer_sequence -> std::integer_sequence.

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@368991 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/clangd/Function.h b/clangd/Function.h
index 91aaa48..3333662 100644
--- a/clangd/Function.h
+++ b/clangd/Function.h
@@ -46,7 +46,7 @@
 
 private:
   template <std::size_t... Indexes, class... RestArgs>
-  auto CallImpl(llvm::integer_sequence<std::size_t, Indexes...> Seq,
+  auto CallImpl(std::integer_sequence<std::size_t, Indexes...> Seq,
                 RestArgs &&... Rest)
       -> decltype(std::get<0>(this->FuncWithArguments)(
           std::forward<Args>(std::get<Indexes + 1>(this->FuncWithArguments))...,