Introduce KProperty{0,1,2}.getDelegate

#KT-8384 In Progress

compiler/testData/codegen/box/reflection/properties/getDelegate/extensionProperty.kt

@@ -0,0 +1,25 @@
+// IGNORE_BACKEND: JS
+// WITH_REFLECT
+
+import kotlin.reflect.KProperty
+import kotlin.reflect.jvm.isAccessible
+import kotlin.test.*
+
+object Delegate {
+    var storage = ""
+    operator fun getValue(instance: Any?, property: KProperty<*>) = storage
+    operator fun setValue(instance: Any?, property: KProperty<*>, value: String) { storage = value }
+}
+
+class Foo
+
+var Foo.result: String by Delegate
+
+fun box(): String {
+    val foo = Foo()
+    foo.result = "Fail"
+    val d = Foo::result.apply { isAccessible = true }.getDelegate(foo) as Delegate
+    foo.result = "OK"
+    assertEquals(d, Foo::result.apply { isAccessible = true }.getDelegate(foo))
+    return d.getValue(foo, Foo::result)
+}