[K/N][tests] Added a test on stack allocated string

kotlin-native/backend.native/tests/codegen/escapeAnalysis/string.kt

@@ -0,0 +1,14 @@
+/*
+ * Copyright 2010-2021 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.
+ */
+
+package codegen.escapeAnalysis.string
+
+import kotlin.test.*
+import kotlin.native.internal.*
+
+@Test fun runTest() {
+    val s = String()
+    assertTrue(s.isLocal())
+}