Index: lib/IR/Attributes.cpp
===================================================================
--- lib/IR/Attributes.cpp
+++ lib/IR/Attributes.cpp
@@ -539,7 +539,8 @@
 }
 
 std::pair<unsigned, Optional<unsigned>> AttributeSet::getAllocSizeArgs() const {
-  return SetNode ? SetNode->getAllocSizeArgs() : std::make_pair(0, 0);
+  return SetNode ? SetNode->getAllocSizeArgs()
+                 : std::pair<unsigned, Optional<unsigned>>(0, 0);
 }
 
 std::string AttributeSet::getAsString(bool InAttrGrp) const {