Support is/as/as? with Function[K]<...> types.

compiler/testData/codegen/boxWithStdlib/casts/reifiedAsFunKSmall.kt

@@ -0,0 +1,36 @@
+fun fn0() {}
+fun fn1(x: Any) {}
+
+inline fun <reified T> reifiedAsSucceeds(x: Any, operation: String) {
+    try {
+        x as T
+    }
+    catch (e: Throwable) {
+        throw AssertionError("$operation: should not throw exceptions, got $e")
+    }
+}
+
+inline fun <reified T> reifiedAsFailsWithCCE(x: Any, operation: String) {
+    try {
+        x as T
+    }
+    catch (e: java.lang.ClassCastException) {
+        return
+    }
+    catch (e: Throwable) {
+        throw AssertionError("$operation: should throw ClassCastException, got $e")
+    }
+    throw AssertionError("$operation: should fail with CCE, no exception thrown")
+}
+
+fun box(): String {
+    val f0 = ::fn0 as Any
+    val f1 = ::fn1 as Any
+
+    reifiedAsSucceeds<Function0<*>>(f0, "f0 as Function0<*>")
+    reifiedAsFailsWithCCE<Function1<*, *>>(f0, "f0 as Function1<*, *>")
+    reifiedAsFailsWithCCE<Function0<*>>(f1, "f1 as Function0<*>")
+    reifiedAsSucceeds<Function1<*, *>>(f1, "f1 as Function1<*, *>")
+
+    return "OK"
+}