JVM_IR KT-47939 use FunInterfaceConstructorReference as base class

compiler/testData/codegen/box/callableReference/funInterfaceConstructor/funInterfaceConstructorIsKFunction.kt

@@ -0,0 +1,24 @@
+// !LANGUAGE: +KotlinFunInterfaceConstructorReference
+
+// DONT_TARGET_EXACT_BACKEND: JVM
+//  ^ old JVM BE generates bogus code
+
+// IGNORE_BACKEND: JS
+//  ^ Failed: kr is class Function1
+
+// WITH_REFLECT
+
+import kotlin.reflect.KFunction
+
+fun interface KRunnable {
+    fun run()
+}
+
+val kr = ::KRunnable // : KFunction1<() -> Unit, KRunnable>
+
+fun box(): String {
+    return if (kr is KFunction<*>)
+        "OK"
+    else
+        "Failed: kr is ${kr::class}"
+}

compiler/testData/codegen/box/callableReference/funInterfaceConstructor/funInterfaceConstructorOfImplicitKFunctionType.kt

@@ -0,0 +1,16 @@
+// !LANGUAGE: +KotlinFunInterfaceConstructorReference
+
+// IGNORE_BACKEND: JVM
+//  ^ unsupported in old JVM BE
+
+fun interface KRunnable {
+    fun run()
+}
+
+val kr = ::KRunnable // : KFunction1<() -> Unit, KRunnable>
+
+fun box(): String {
+    var test = "Failed"
+    kr { test = "OK" }.run()
+    return test
+}