Implement proper contract for generated java.lang.Annotation.hashCode()

#KT-48606 Fixed

compiler/testData/codegen/box/annotations/instances/annotationEqHc.kt

@@ -20,14 +20,14 @@ annotation class Foo(
     val bar: Bar
 )
 
-data class BarLike(val i:Int, val s: String, val f: Float)
+fun makeHC(name: String, value: Any) = (127 * name.hashCode()) xor value.hashCode()
 
 fun box(): String {
     val foo1 = Foo(42, "foo", arrayOf("a", "b"), intArrayOf(1,2), Bar::class, Bar(10, "bar", Float.NaN))
     val foo2 = Foo(42, "foo", arrayOf("a", "b"), intArrayOf(1,2), Bar::class, Bar(10, "bar", Float.NaN))
     if (foo1 != foo2) return "Failed equals ${foo1.toString()} ${foo2.toString()}"
-    val barlike = BarLike(10, "bar", Float.NaN)
-    if (barlike.hashCode() != foo1.bar.hashCode()) return "Failed HC1"
-    if (barlike.hashCode() != foo2.bar.hashCode()) return "Failed HC2"
+    val barlike = makeHC("i", 10) + makeHC("s", "bar") + makeHC("f", Float.NaN)
+    if (barlike != foo1.bar.hashCode()) return "Failed HC1"
+    if (barlike != foo2.bar.hashCode()) return "Failed HC2"
     return "OK"
 }

compiler/testData/codegen/box/annotations/instances/annotationJvmHashCode.kt

@@ -0,0 +1,35 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+// TARGET_BACKEND: JVM_IR
+
+// WITH_RUNTIME
+// !LANGUAGE: +InstantiationOfAnnotationClasses
+
+import kotlin.reflect.KClass
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue as assert
+
+annotation class ZeroArg()
+
+annotation class OneArg(val arg: String)
+
+annotation class ManyArg(val i: Int, val o: OneArg, val z: Boolean, val k: KClass<*>, val e: IntArray)
+
+@ZeroArg
+@OneArg("a")
+@ManyArg(42, OneArg("b"), true, OneArg::class, intArrayOf(1, 2, 3))
+class Target
+
+fun box(): String {
+    val reflectiveZero = Target::class.java.getAnnotation(ZeroArg::class.java)
+    val reflectiveOne = Target::class.java.getAnnotation(OneArg::class.java)
+    val reflectiveMany = Target::class.java.getAnnotation(ManyArg::class.java)
+
+    val createdZero = ZeroArg()
+    val createdOne = OneArg("a")
+    val createdMany = ManyArg(42, OneArg("b"), true, OneArg::class, intArrayOf(1, 2, 3))
+
+    assertEquals(reflectiveZero.hashCode(), createdZero.hashCode(), "zero")
+    assertEquals(reflectiveOne.hashCode(), createdOne.hashCode(), "one")
+    assertEquals(reflectiveMany.hashCode(), createdMany.hashCode(), "many")
+    return "OK"
+}