[K/N] Do not compile for deprecated targets and legacy MM

^KT-56533
^KT-58853

kotlin-native/backend.native/tests/interop/memory_leaks/lib.kt

@@ -1,15 +0,0 @@
-/*
- * 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.
- */
-
-import kotlinx.cinterop.*
-import kotlin.native.Platform
-
-fun enableMemoryChecker() {
-    Platform.isMemoryLeakCheckerActive = true
-}
-
-fun leakMemory() {
-    StableRef.create(Any())
-}

kotlin-native/backend.native/tests/interop/memory_leaks/main.cpp

@@ -1,17 +0,0 @@
-/*
- * 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.
- */
-
-#include "testlib_api.h"
-
-#include <thread>
-
-int main() {
-    std::thread t([]() {
-        testlib_symbols()->kotlin.root.enableMemoryChecker();
-        testlib_symbols()->kotlin.root.leakMemory();
-    });
-    t.join();
-    return 0;
-}