Merge boxWithStdlib testData into box, delete BoxWithStdlib test

compiler/testData/codegen/box/regressions/kt1406.kt

@@ -0,0 +1,28 @@
+// WITH_RUNTIME
+// FULL_JDK
+
+package pack
+
+import java.util.ArrayList
+import java.util.regex.Pattern
+
+class C{
+    public fun foo(){
+        val items : Collection<Item> = java.util.Collections.singleton(Item())!!
+        val result = ArrayList<Item>()
+        val pattern: Pattern? = Pattern.compile("...")
+        items.filterTo(result) {
+            pattern!!.matcher(it.name())!!.matches()
+        }
+    }
+
+    private fun Item.name() : String = ""
+}
+
+class Item{
+}
+
+fun box() : String {
+    C().foo()
+    return "OK"
+}