Straighten Char-to-code and Char-to-digit conversions out #KT-23451

(cherry picked from commit 4c0c46e87def97f9102da9df72331ebcfee09aab)

kotlin-native/runtime/src/main/kotlin/kotlin/CharCode.kt

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2010-2020 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
+
+/**
+ * Creates a Char with the specified [code].
+ *
+ * @sample samples.text.Chars.charFromCode
+ */
+@OptIn(ExperimentalUnsignedTypes::class)
+@ExperimentalStdlibApi
+@SinceKotlin("1.4")
+@kotlin.internal.InlineOnly
+public actual inline fun Char(code: UShort): Char {
+    return code.toInt().toChar()
+}