[SLC] introduce CompositeAnnotationsProvider

^KT-56046

analysis/symbol-light-classes/src/org/jetbrains/kotlin/light/classes/symbol/annotations/CompositeAnnotationsProvider.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.light.classes.symbol.annotations
+
+import org.jetbrains.kotlin.analysis.api.annotations.KtAnnotationApplication
+import org.jetbrains.kotlin.name.ClassId
+
+internal class CompositeAnnotationsProvider(val providers: Collection<AnnotationsProvider>) : AnnotationsProvider {
+    override fun classIds(): Collection<ClassId> = buildList {
+        for (provider in providers) {
+            addAll(provider.classIds())
+        }
+    }
+
+    override fun get(classId: ClassId): Collection<KtAnnotationApplication> = buildList {
+        for (provider in providers) {
+            addAll(provider[classId])
+        }
+    }
+
+    override fun contains(classId: ClassId): Boolean = providers.any { classId in it }
+
+    override fun isTheSameAs(other: Any?): Boolean = other === this ||
+            other is CompositeAnnotationsProvider &&
+            other.providers.size == providers.size &&
+            other.providers.zip(providers).all { (another, myProvider) ->
+                myProvider.isTheSameAs(another)
+            }
+
+    override fun ownerClassId(): ClassId? = null
+}