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/StringTest/replace.kt

@@ -0,0 +1,14 @@
+import kotlin.test.*
+
+
+
+fun box() {
+    val input = "abbAb"
+    assertEquals("abb${'$'}b", input.replace('A', '$'))
+    assertEquals("/bb/b", input.replace('A', '/', ignoreCase = true))
+
+    assertEquals("${'$'}bAb", input.replace("ab", "$"))
+    assertEquals("/b/", input.replace("ab", "/", ignoreCase = true))
+
+    assertEquals("-a-b-b-A-b-", input.replace("", "-"))
+}