Move JVM8 box test to common

compiler/testData/codegen/box/jvm8/simpleProperty.kt

@@ -0,0 +1,14 @@
+// TARGET_BACKEND: JVM
+// JVM_TARGET: 1.8
+
+interface Z {
+    val z: String
+        get() = "OK"
+}
+
+
+class Test : Z
+
+fun box() : String {
+    return Test().z
+}