re-allow non-final classes to have move-only members

Author: kavon

include/swift/AST/DiagnosticsSema.def

@@ -6919,8 +6919,6 @@ NOTE(moveonly_copyable_type_that_contains_moveonly_type_location, none,
 ERROR(moveonly_cannot_conform_to_type, none,
      "move-only %0 %1 cannot conform to %2",
      (DescriptiveDeclKind, DeclName, Type))
-ERROR(moveonly_non_final_class_cannot_contain_moveonly_field, none,
-     "non-final classes containing move only fields is not yet supported", ())
 ERROR(moveonly_parameter_missing_ownership, none,
       "noncopyable parameter must specify its ownership", ())
 NOTE(moveonly_parameter_ownership_suggestion, none,

lib/Sema/TypeCheckDeclPrimary.cpp

@@ -2968,15 +2968,6 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
 
     diagnoseIncompatibleProtocolsForMoveOnlyType(CD);
 
-    // Ban non-final classes from having move only fields.
-    if (!CD->isFinal()) {
-      for (auto *field : CD->getStoredProperties()) {
-        if (field->getType()->isPureMoveOnly()) {
-          field->diagnose(
-              diag::moveonly_non_final_class_cannot_contain_moveonly_field);
-        }
-      }
-    }
   }
 
   void visitProtocolDecl(ProtocolDecl *PD) {