Index: lib/Sema/SemaOverload.cpp
===================================================================
--- lib/Sema/SemaOverload.cpp
+++ lib/Sema/SemaOverload.cpp
@@ -10516,7 +10516,7 @@
     }
   }
 
-  std::sort(Cands.begin(), Cands.end(),
+  std::stable_sort(Cands.begin(), Cands.end(),
             CompareOverloadCandidatesForDisplay(S, OpLoc, Args.size(), Kind));
 
   bool ReportedAmbiguousConversions = false;