[K/N] Move kotlin.native.internal.GC into kotlin.native.runtime

As a part of efforts to stabilize Native stdlib #KT-55765.

kotlin-native/backend.native/tests/objcexport/coroutines.kt

@@ -2,6 +2,7 @@
  * Copyright 2010-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
  * that can be found in the LICENSE file.
  */
+@file:OptIn(kotlin.native.runtime.NativeRuntimeApi::class)
 
 package coroutines
 
@@ -243,4 +244,4 @@ fun createCoroutineUninterceptedAndResume(fn: suspend () -> Any?, resultHolder:
 fun createCoroutineUninterceptedAndResume(fn: suspend Any?.() -> Any?, receiver: Any?, resultHolder: ResultHolder<Any?>) =
         fn.createCoroutine(receiver, ResultHolderCompletion(resultHolder)).resume(Unit)
 
-fun gc() = kotlin.native.internal.GC.collect()
+fun gc() = kotlin.native.runtime.GC.collect()

kotlin-native/backend.native/tests/objcexport/deallocRetain.kt

@@ -7,7 +7,8 @@ package deallocretain
 
 open class DeallocRetainBase
 
-fun garbageCollect() = kotlin.native.internal.GC.collect()
+@OptIn(kotlin.native.runtime.NativeRuntimeApi::class)
+fun garbageCollect() = kotlin.native.runtime.GC.collect()
 
 fun createWeakReference(value: Any) = kotlin.native.ref.WeakReference(value)
 

kotlin-native/backend.native/tests/objcexport/noAutorelease.kt

@@ -19,7 +19,8 @@ class KotlinLivenessTracker {
     fun objectsAreDead() = weakRefs.all { it.value === null }
 }
 
-fun gc() = kotlin.native.internal.GC.collect()
+@OptIn(kotlin.native.runtime.NativeRuntimeApi::class)
+fun gc() = kotlin.native.runtime.GC.collect()
 
 class KotlinObject
 

kotlin-native/backend.native/tests/objcexport/values.kt

@@ -5,7 +5,7 @@
 
 // All classes and methods should be used in tests
 @file:Suppress("UNUSED")
-@file:OptIn(FreezingIsDeprecated::class)
+@file:OptIn(FreezingIsDeprecated::class, kotlin.native.runtime.NativeRuntimeApi::class)
 
 package conversions
 
@@ -807,7 +807,7 @@ open class TestDeprecation() {
 @Deprecated("warning", level = DeprecationLevel.WARNING) var warningVar: Any? = null
 
 fun gc() {
-    kotlin.native.internal.GC.collect()
+    kotlin.native.runtime.GC.collect()
 }
 
 class TestWeakRefs(private val frozen: Boolean) {
@@ -862,7 +862,7 @@ class SharedRefs {
     fun createFrozenCollection() = createCollection().freeze()
 
     fun hasAliveObjects(): Boolean {
-        kotlin.native.internal.GC.collect()
+        kotlin.native.runtime.GC.collect()
         return mustBeRemoved.any { it.get() != null }
     }