Migrate boxWithJava tests to multi-file framework

compiler/testData/codegen/boxWithJava/reflection/javaPropertyInheritedInKotlin.kt

@@ -0,0 +1,17 @@
+// FILE: J.java
+
+public class J {
+    public String result = null;
+}
+
+// FILE: K.kt
+
+class K : J()
+
+fun box(): String {
+    val k = K()
+    val p = K::result
+    if (p.get(k) != null) return "Fail"
+    p.set(k, "OK")
+    return p.get(k)
+}