tests: Copy stdlib tests from Kotlin/JVM

This patch copies Kotlin/JVM stdlib tests (libraries/stdlib/test)
excepting ones with explicit java dependencies. It also transforms
the tests to use them as box-tests.

backend.native/tests/external/stdlib/collections/CollectionTest/minusIsEager.kt

@@ -0,0 +1,13 @@
+import kotlin.test.*
+import kotlin.comparisons.*
+
+fun box() {
+    val source = listOf("foo", "bar")
+    val list = arrayListOf<String>()
+    val result = source - list
+
+    list += "foo"
+    assertEquals(source, result)
+    list += "bar"
+    assertEquals(source, result)
+}