FIR: Copy attributes when copying declaration

Otherwise they share FirDeclarationAttributes instance that might lead
to problems when modifying only one of them

compiler/fir/cones/src/org/jetbrains/kotlin/fir/utils/ArrayMap.kt

@@ -10,6 +10,8 @@ sealed class ArrayMap<T : Any> : Iterable<T> {
 
     abstract operator fun set(index: Int, value: T)
     abstract operator fun get(index: Int): T?
+
+    abstract fun copy(): ArrayMap<T>
 }
 
 fun ArrayMap<*>.isEmpty(): Boolean = size == 0
@@ -27,6 +29,8 @@ internal object EmptyArrayMap : ArrayMap<Nothing>() {
         return null
     }
 
+    override fun copy(): ArrayMap<Nothing> = this
+
     override fun iterator(): Iterator<Nothing> {
         return object : Iterator<Nothing> {
             override fun hasNext(): Boolean = false
@@ -48,6 +52,8 @@ internal class OneElementArrayMap<T : Any>(val value: T, val index: Int) : Array
         return if (index == this.index) value else null
     }
 
+    override fun copy(): ArrayMap<T> = OneElementArrayMap(value, index)
+
     override fun iterator(): Iterator<T> {
         return object : Iterator<T> {
             private var notVisited = true
@@ -68,16 +74,20 @@ internal class OneElementArrayMap<T : Any>(val value: T, val index: Int) : Array
     }
 }
 
-internal class ArrayMapImpl<T : Any> : ArrayMap<T>() {
+internal class ArrayMapImpl<T : Any> private constructor(
+    private var data: Array<Any?>
+) : ArrayMap<T>() {
     companion object {
         private const val DEFAULT_SIZE = 20
         private const val INCREASE_K = 2
     }
 
+    constructor() : this(arrayOfNulls<Any>(DEFAULT_SIZE))
+
     override var size: Int = 0
         private set
 
-    private var data = arrayOfNulls<Any>(DEFAULT_SIZE)
+
     private fun ensureCapacity(index: Int) {
         if (data.size <= index) {
             data = data.copyOf(data.size * INCREASE_K)
@@ -97,6 +107,8 @@ internal class ArrayMapImpl<T : Any> : ArrayMap<T>() {
         return data.getOrNull(index) as T?
     }
 
+    override fun copy(): ArrayMap<T> = ArrayMapImpl(data.copyOf())
+
     override fun iterator(): Iterator<T> {
         return object : AbstractIterator<T>() {
             private var index = -1
@@ -128,4 +140,4 @@ internal class ArrayMapImpl<T : Any> : ArrayMap<T>() {
     }
 
     data class Entry<T>(override val key: Int, override val value: T) : Map.Entry<Int, T>
-}
+}

compiler/fir/cones/src/org/jetbrains/kotlin/fir/utils/AttributeArrayOwner.kt

@@ -17,11 +17,15 @@ import kotlin.reflect.KClass
  *   from components in [ComponentArrayOwner]
  */
 @OptIn(Protected::class)
-abstract class AttributeArrayOwner<K : Any, T : Any> : AbstractArrayMapOwner<K, T>() {
-    @Suppress("UNCHECKED_CAST")
-    final override var arrayMap: ArrayMap<T> = EmptyArrayMap as ArrayMap<T>
+abstract class AttributeArrayOwner<K : Any, T : Any> protected constructor(
+    arrayMap: ArrayMap<T>
+) : AbstractArrayMapOwner<K, T>() {
+    final override var arrayMap: ArrayMap<T> = arrayMap
         private set
 
+    @Suppress("UNCHECKED_CAST")
+    constructor() : this(EmptyArrayMap as ArrayMap<T>)
+
     final override fun registerComponent(tClass: KClass<out K>, value: T) {
         val id = typeRegistry.getId(tClass)
         when (arrayMap.size) {
@@ -61,4 +65,4 @@ abstract class AttributeArrayOwner<K : Any, T : Any> : AbstractArrayMapOwner<K,
             }
         }
     }
-}
+}