[K/N] Enable new mm for native by default

native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/NativeTestSupport.kt

@@ -173,7 +173,7 @@ private object NativeTestSupport {
         )
 
     private fun computeMemoryModel(enforcedProperties: EnforcedProperties): MemoryModel =
-        ClassLevelProperty.MEMORY_MODEL.readValue(enforcedProperties, MemoryModel.values(), default = MemoryModel.DEFAULT)
+        ClassLevelProperty.MEMORY_MODEL.readValue(enforcedProperties, MemoryModel.values(), default = MemoryModel.EXPERIMENTAL)
 
     private fun computeThreadStateChecker(enforcedProperties: EnforcedProperties): ThreadStateChecker {
         val useThreadStateChecker =

native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/settings/TestProcessSettings.kt

@@ -89,7 +89,11 @@ internal enum class OptimizationMode(private val description: String, val compil
  * The Kotlin/Native memory model.
  */
 internal enum class MemoryModel(val compilerFlags: List<String>?) {
-    DEFAULT(null),
+    /**
+     * TODO: rename DEFAULT to LEGACY. It was postponed, as it would require simultaneous change in teamcity configuration
+     * but it should be done at some point.
+     */
+    DEFAULT(listOf("-memory-model", "strict")),
     EXPERIMENTAL(listOf("-memory-model", "experimental"));
 
     override fun toString() = compilerFlags?.joinToString(prefix = "(", separator = " ", postfix = ")").orEmpty()