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/SequenceTest/sequenceFromFunction.kt

@@ -0,0 +1,19 @@
+import kotlin.test.*
+
+import kotlin.comparisons.*
+
+fun box() {
+    var count = 3
+
+    val sequence = generateSequence {
+        count--
+        if (count >= 0) count else null
+    }
+
+    val list = sequence.toList()
+    assertEquals(listOf(2, 1, 0), list)
+
+    assertFails {
+        sequence.toList()
+    }
+}