Supported renaming of default object. Named only objects are supported

yet.

idea/testData/refactoring/rename/defaultObject/before/javaUsage.java

@@ -0,0 +1,8 @@
+class JavaUsage {
+    public static void main(String[] args) {
+        System.out.println(Foo.CONST);
+        Foo.s();
+        Foo.Bar.f();
+        Foo foo = new Foo(); // not usage of default object
+    }
+}

idea/testData/refactoring/rename/defaultObject/before/toBeRenamed.kt

@@ -0,0 +1,11 @@
+class Foo {
+    default object Bar {
+        fun f() {
+        }
+
+        platformStatic fun s() {
+        }
+
+        val CONST = 42
+    }
+}

idea/testData/refactoring/rename/defaultObject/before/usage.kt

@@ -0,0 +1,8 @@
+fun main(args: Array<String>) {
+    // class object usages
+    Foo.f()
+    val x = Foo
+
+    Foo.Bar.f()
+    val xx = Foo.Bar
+}