Introduce KProperty{0,1,2}.getDelegate

#KT-8384 In Progress

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

@@ -0,0 +1,42 @@
+// IGNORE_BACKEND: JS
+// WITH_REFLECT
+
+import kotlin.reflect.*
+import kotlin.reflect.full.extensionReceiverParameter
+import kotlin.reflect.jvm.isAccessible
+import kotlin.test.*
+
+class Delegate(val value: String) {
+    operator fun getValue(instance: Any?, property: KProperty<*>) = value
+}
+
+class Foo
+
+val Foo.bar: String by Delegate("Foo")
+val String.bar: String by Delegate("String")
+val Unit.bar: String by Delegate("Unit")
+
+class MemberExtensions {
+    val Foo?.bar: String by Delegate("Foo")
+    val String?.bar: String by Delegate("String")
+    val Unit?.bar: String by Delegate("Unit")
+}
+
+fun box(): String {
+    val foo = Foo()
+
+    assertEquals("Foo", ((foo::bar).apply { isAccessible = true }.getDelegate() as Delegate).value)
+    assertEquals("Foo", ((Foo::bar).apply { isAccessible = true }.getDelegate(foo) as Delegate).value)
+    assertEquals("String", ((""::bar).apply { isAccessible = true }.getDelegate() as Delegate).value)
+    assertEquals("String", ((String::bar).apply { isAccessible = true }.getDelegate("") as Delegate).value)
+    assertEquals("Unit", ((Unit::bar).apply { isAccessible = true }.getDelegate() as Delegate).value)
+
+    val me = MemberExtensions::class.members.filter { it.name == "bar" } as List<KProperty2<MemberExtensions, Any?, String>>
+    assertEquals(listOf("Foo", "String", "Unit"), me.sortedBy {
+        it.extensionReceiverParameter!!.type.toString()
+    }.map {
+        (it.apply { isAccessible = true }.getDelegate(MemberExtensions(), null) as Delegate).value
+    })
+
+    return "OK"
+}