Move UArraysKt into kotlin.collections.unsigned package

Provide UArraysKt class in kotlin.collections for binary compatibility
instead of removed multipart facade class. It contains only non-inline
functions of the latter.

libraries/stdlib/common/src/generated/_UArrays.kt

@@ -5,6 +5,7 @@
 
 @file:kotlin.jvm.JvmMultifileClass
 @file:kotlin.jvm.JvmName("UArraysKt")
+@file:kotlin.jvm.JvmPackageName("kotlin.collections.unsigned")
 
 package kotlin.collections