KT-23356 Cross-platform function to convert CharArray slice to String

Signed-off-by: Valeriy Zhirnov <neonailol@gmail.com>

libraries/stdlib/js/src/kotlin/string.kt

@@ -7,6 +7,24 @@ package kotlin.text
 
 import kotlin.js.RegExp
 
+/**
+ * Converts the characters in the specified array to a string.
+ */
+@SinceKotlin("1.2")
+@kotlin.internal.InlineOnly
+public actual inline fun String(chars: CharArray): String {
+    return js("String.fromCharCode").apply(null, chars)
+}
+
+/**
+ * Converts the characters from a portion of the specified array to a string.
+ */
+@SinceKotlin("1.2")
+public actual fun String(chars: CharArray, offset: Int, length: Int): String {
+    return String(chars.copyOfRange(offset, offset + length))
+}
+
+
 @kotlin.internal.InlineOnly
 public actual inline fun String.toUpperCase(): String = asDynamic().toUpperCase()