Move java 8+defaults tests to separate folder

compiler/testData/codegen/java8/box/jvm8/defaults/oneImplementation.kt

@@ -0,0 +1,20 @@
+// JVM_TARGET: 1.8
+// KOTLIN_CONFIGURATION_FLAGS: +JVM.JVM8_TARGET_WITH_DEFAULTS
+interface KCallable {
+    val returnType: String
+}
+
+interface KCallableImpl : KCallable {
+    override val returnType: String
+        get() = "OK"
+}
+
+interface KCallableImpl2 : KCallableImpl
+
+open class DescriptorBasedProperty : KCallableImpl
+open class KProperty1Impl : DescriptorBasedProperty(), KCallableImpl2
+open class KMutableProperty1Impl : KProperty1Impl(), KCallable
+
+fun box(): String {
+    return KMutableProperty1Impl().returnType
+}