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/text/RegexTest/matchEntireLazyQuantor.kt

@@ -0,0 +1,12 @@
+import kotlin.text.*
+
+import kotlin.test.*
+
+
+fun box() {
+    val regex = "a+b+?".toRegex()
+    val input = StringBuilder("aaaabbbb")
+
+    assertEquals("aaaab", regex.find(input)!!.value)
+    assertEquals("aaaabbbb", regex.matchEntire(input)!!.value)
+}