AST: Bring back old meaning of mayHaveSuperclass()

Author: slavapestov

include/swift/AST/Types.h

@@ -4552,21 +4552,6 @@ inline CanType CanType::getNominalParent() const {
   }
 }
 
-inline bool TypeBase::mayHaveSuperclass() {
-  if (getClassOrBoundGenericClass())
-    return true;
-
-  // FIXME: requiresClass() is not the same as having an explicit superclass;
-  // is this wrong?
-  if (auto archetype = getAs<ArchetypeType>())
-    return (bool)archetype->requiresClass();
-
-  if (isExistentialType())
-    return (bool)getSuperclass(nullptr);
-
-  return is<DynamicSelfType>();
-}
-
 inline TupleTypeElt::TupleTypeElt(Type ty, Identifier name, bool isVariadic,
                                   bool isAutoClosure, bool isEscaping)
     : Name(name), ElementType(ty),

lib/AST/Type.cpp

@@ -1562,6 +1562,16 @@ LayoutConstraint TypeBase::getLayoutConstraint() {
   return LayoutConstraint();
 }
 
+bool TypeBase::mayHaveSuperclass() {
+  if (getClassOrBoundGenericClass())
+    return true;
+
+  if (auto archetype = getAs<ArchetypeType>())
+    return (bool)archetype->requiresClass();
+
+  return is<DynamicSelfType>();
+}
+
 Type TypeBase::getSuperclass(LazyResolver *resolver) {
   auto *nominalDecl = getAnyNominal();
   auto *classDecl = dyn_cast_or_null<ClassDecl>(nominalDecl);