SIL: Correct handling of local archetypes in remapConformance()

Author: slavapestov

include/swift/SIL/TypeSubstCloner.h

@@ -226,21 +226,12 @@ class TypeSubstCloner : public SILClonerWithScopes<ImplClass> {
 
   ProtocolConformanceRef remapConformance(Type ty,
                                           ProtocolConformanceRef conf) {
-    // If we have local archetypes to substitute, do so now.
-    if (ty->hasLocalArchetype() && !LocalArchetypeSubs.empty()) {
-      conf =
-        conf.subst(ty,
-                   QueryTypeSubstitutionMapOrIdentity{LocalArchetypeSubs},
-                   MakeAbstractConformanceForGenericType());
-      ty = ty.subst(
-            QueryTypeSubstitutionMapOrIdentity{LocalArchetypeSubs},
-            MakeAbstractConformanceForGenericType());
-    }
+    SubstitutionMapWithLocalArchetypes functor(SubsMap, LocalArchetypeSubs);
+    auto substTy = ty.subst(functor, functor)->getCanonicalType();
+    auto substConf = conf.subst(ty, functor, functor);
 
     auto context = getBuilder().getTypeExpansionContext();
 
-    auto substTy = ty.subst(SubsMap)->getCanonicalType();
-    auto substConf = conf.subst(ty, SubsMap);
     if (!substTy->hasOpaqueArchetype() ||
         !context.shouldLookThroughOpaqueTypeArchetypes())
       return substConf;