Add protobuf extensions to serialized Java descriptors

#KT-17621 In Progress

build-common/src/java_descriptors.proto

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.serialization.java;
+
+import "core/deserialization/src/descriptors.proto";
+
+option java_outer_classname = "JavaClassProtoBuf";
+option optimize_for = LITE_RUNTIME;
+
+extend Function {
+  optional bool is_static_method = 1000;
+  optional bool is_package_private_method = 1001;
+}
+
+extend Property {
+  optional bool is_static_field = 1000;
+  optional bool is_package_private_field = 1001;
+}
+
+extend Class {
+  optional bool is_package_private_class = 1000;
+}
+
+extend Constructor {
+  optional bool is_package_private_constructor = 1000;
+}