Stabilize Char-to-Int conversions KT-45874

libraries/stdlib/wasm/src/kotlin/CharCode.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 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.
  */
 
@@ -10,7 +10,5 @@ package kotlin
  *
  * @sample samples.text.Chars.charFromCode
  */
-@OptIn(ExperimentalUnsignedTypes::class)
-@ExperimentalStdlibApi
-@SinceKotlin("1.4")
+@SinceKotlin("1.5")
 public actual fun Char(code: UShort): Char = TODO("Wasm stdlib: CharCode")