Support KClass.isInstance/cast/safeCast in stdlib-only reflection implementation

#KT-14720 Fixed

compiler/testData/codegen/box/reflection/isInstance/isInstanceCastAndSafeCast.kt

@@ -1,10 +1,10 @@
+// !USE_EXPERIMENTAL: kotlin.ExperimentalStdlibApi
 // TARGET_BACKEND: JVM
-
-// WITH_REFLECT
+// WITH_RUNTIME
 
 import kotlin.reflect.KClass
-import kotlin.reflect.full.cast
-import kotlin.reflect.full.safeCast
+import kotlin.reflect.cast
+import kotlin.reflect.safeCast
 import kotlin.test.*
 
 fun testInstance(value: Any?, klass: KClass<*>) {

compiler/testData/diagnostics/tests/reflection/noReflectionInClassPath.kt

@@ -39,6 +39,7 @@ fun <T : Any> kclass(k: KClass<*>, kt: KClass<T>) {
     k.<!NO_REFLECTION_IN_CLASS_PATH!>isCompanion<!>
 
     k.<!NO_REFLECTION_IN_CLASS_PATH!>annotations<!>
+    k.isInstance(42)
 
     k == kt
     k.hashCode()