[K/N] Mark BitSet usages in stdlib with @ObsoleteNativeApi

libraries/stdlib/native-wasm/src/kotlin/text/regex/AbstractCharClass.kt

@@ -28,6 +28,7 @@ import kotlin.native.concurrent.AtomicReference
 import kotlin.native.concurrent.freeze
 import kotlin.native.BitSet
 import kotlin.native.FreezingIsDeprecated
+import kotlin.native.ObsoleteNativeApi
 
 /**
  * Unicode category (i.e. Ll, Lu).
@@ -49,7 +50,7 @@ internal class UnicodeCategoryScope(category: Int) : UnicodeCategory(category) {
  * This class represents character classes, i.e. sets of character either predefined or user defined.
  * Note: this class represent a token, not node, so being constructed by lexer.
  */
-@OptIn(FreezingIsDeprecated::class)
+@OptIn(FreezingIsDeprecated::class, ObsoleteNativeApi::class)
 internal abstract class AbstractCharClass : SpecialToken() {
     /**
      * Show if the class has alternative meaning:

libraries/stdlib/native-wasm/src/kotlin/text/regex/CharClass.kt

@@ -23,11 +23,13 @@
 package kotlin.text.regex
 
 import kotlin.native.BitSet
+import kotlin.native.ObsoleteNativeApi
 
 /**
  * User defined character classes (e.g. [abef]).
  */
 // TODO: replace the implementation with one using BitSet for first 256 symbols and a hash table / tree for the rest of UTF.
+@OptIn(ObsoleteNativeApi::class)
 internal class CharClass(val ignoreCase: Boolean = false, negative: Boolean = false)  : AbstractCharClass()  {
 
     var invertedSurrogates = false

libraries/stdlib/wasm/src/kotlin/text/regex/ObsoleteNativeApi.kt

@@ -0,0 +1,33 @@
+/*
+ * 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 kotlin.native
+
+import kotlin.annotation.AnnotationTarget.*
+
+/**
+ * This annotation marks the Kotlin/Native standard library API that is considered obsolete and is being phased out.
+ *
+ * This is an internal copy of the public K/N annotation.
+ * It is used to [OptIn] obsolete K/N API used in the shared native-wasm directory.
+ */
+@RequiresOptIn(message = "This API is obsolete and subject to removal in a future release.", level = RequiresOptIn.Level.WARNING)
+@Retention(AnnotationRetention.BINARY)
+@Target(
+    AnnotationTarget.CLASS,
+    AnnotationTarget.ANNOTATION_CLASS,
+    AnnotationTarget.PROPERTY,
+    AnnotationTarget.FIELD,
+    AnnotationTarget.LOCAL_VARIABLE,
+    AnnotationTarget.VALUE_PARAMETER,
+    AnnotationTarget.CONSTRUCTOR,
+    AnnotationTarget.FUNCTION,
+    AnnotationTarget.PROPERTY_GETTER,
+    AnnotationTarget.PROPERTY_SETTER,
+    AnnotationTarget.TYPEALIAS
+)
+@MustBeDocumented
+@SinceKotlin("1.9")
+internal annotation class ObsoleteNativeApi