[kotlinp] Fix: Forgotten sorting of KmClasses in KlibKotlinp

The declarations that are printed by the kotlinp tool may be optionally
sorted. That's controlled by `sortDeclarations` flag in
`org.jetbrains.kotlin.kotlinp.Settings`. However, there was no sorting
implemented for `KmClass`es.

This commit fixes that.

^KT-62340

libraries/tools/kotlinp/klib/src/org/jetbrains/kotlin/kotlinp/klib/KlibKotlinp.kt

@@ -38,7 +38,7 @@ class KlibKotlinp(
                     appendCommentedLine("class name: ", it)
                 }
             }
-            moduleFragment.classes.forEach { appendLine(); renderClass(it, printer) }
+            moduleFragment.classes.sortIfNeeded { it.sortedBy(KmClass::name) }.forEach { appendLine(); renderClass(it, printer) }
             moduleFragment.pkg?.let { appendLine(); renderPackage(it, printer) }
         }
         appendLine("}")