Migrate boxWithJava tests to multi-file framework

compiler/testData/codegen/boxWithJava/interfaces/abstractClassInheritsFromInterface.kt

@@ -0,0 +1,19 @@
+// FILE: ExtendsKCWithT.java
+
+public class ExtendsKCWithT extends KC {
+    public static String bar() {
+        return new ExtendsKCWithT().foo();
+    }
+}
+
+// FILE: KC.kt
+
+// KT-3407 Implementing (in Java) an abstract Kotlin class that implements a trait does not respect trait method definition
+
+interface  T {
+    fun foo() = "OK"
+}
+
+abstract class KC: T {}
+
+fun box() = ExtendsKCWithT.bar()