Minor. Add regression test for KT-60136

Spread operator works incorrectly in K1, but correctly in K2.
 #KT-60136 Fixed

compiler/testData/codegen/box/reflection/annotations/spread.kt

@@ -0,0 +1,19 @@
+// TARGET_BACKEND: JVM
+// WITH_REFLECT
+// IGNORE_BACKEND_K1: JVM, JVM_IR
+
+@Retention(AnnotationRetention.RUNTIME)
+annotation class A(vararg val xs: String)
+
+@A(*arrayOf("a"), *arrayOf("b"))
+fun test() {}
+
+fun box(): String {
+    val annotation = ::test.annotations.single() as A
+    if (!annotation.xs.contentEquals(arrayOf("a", "b"))) return annotation.toString()
+    return "OK"
+}
+
+fun main() {
+    println(box())
+}