[KT-77056] feat: change visibility of private fields in String class

libraries/stdlib/wasm/builtins/kotlin/String.kt

diff --git a/libraries/stdlib/wasm/builtins/kotlin/String.kt b/libraries/stdlib/wasm/builtins/kotlin/String.kt
index 3d4493d..2749b7f 100644
--- a/libraries/stdlib/wasm/builtins/kotlin/String.kt
+++ b/libraries/stdlib/wasm/builtins/kotlin/String.kt
@@ -13,10 +13,10 @@
  * implemented as instances of this class.
  */
 public actual class String internal @WasmPrimitiveConstructor constructor(
-    private var leftIfInSum: String?,
+    internal var leftIfInSum: String?,
     @kotlin.internal.IntrinsicConstEvaluation
     public actual override val length: Int,
-    private var _chars: WasmCharArray,
+    internal var _chars: WasmCharArray,
 ) : Comparable<String>, CharSequence {
     public actual companion object {}