A couple of functions in stdlib are marked with @InlineExposed.

runtime/src/main/kotlin/kotlin/collections/ArrayUtil.kt

@@ -21,6 +21,7 @@ package kotlin.collections
  * Attempts to read _uninitialized_ values from this array work in implementation-dependent manner,
  * either throwing exception or returning some kind of implementation-specific default value.
  */
+@kotlin.internal.InlineExposed
 internal fun <E> arrayOfUninitializedElements(size: Int): Array<E> {
     // TODO: special case for size == 0?
     return Array<E>(size)
@@ -306,4 +307,4 @@ internal fun <E> Collection<E>.collectionToString(): String {
     }
     sb.append("]")
     return sb.toString()
-}
+}

runtime/src/main/kotlin/kotlin/collections/Maps.kt

@@ -582,7 +582,7 @@ public inline operator fun <K, V> MutableMap<in K, in V>.plusAssign(map: Map<K,
     putAll(map)
 }
 
-// do not expose for now @kotlin.internal.InlineExposed
+@kotlin.internal.InlineExposed
 internal fun <K, V> Map<K, V>.optimizeReadOnlyMap() = when (size) {
     0 -> emptyMap()
 //    1 -> toSingletonMapOrSelf()