Added test cases checking all decompiled files.

idea/testData/libraries/WithTraitClassObject.kt

@@ -0,0 +1,9 @@
+// IntelliJ API Decompiler stub source generated from a class file
+// Implementation of methods is not available
+
+package testData.libraries
+
+class WithTraitClassObject {
+    class object : testData.libraries.SimpleTrait {
+    }
+}