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/plusRanges.kt

@@ -0,0 +1,9 @@
+import kotlin.test.*
+import kotlin.comparisons.*
+
+fun box() {
+    val range1 = 1..3
+    val range2 = 4..7
+    val combined = range1 + range2
+    assertEquals((1..7).toList(), combined)
+}