Merge boxWithStdlib testData into box, delete BoxWithStdlib test

compiler/testData/codegen/box/regressions/kt1800.kt

@@ -0,0 +1,32 @@
+// WITH_RUNTIME
+//KT-1800 error/NonExistentClass generated on runtime
+package i
+
+import java.util.ArrayList
+
+public class User(val firstName: String,
+                  val lastName: String,
+                  val age: Int) {
+    override fun toString() = "$firstName $lastName, age $age"
+}
+
+public fun <T: Comparable<T>> Collection<T>.testMin(): T? {
+    var minValue: T? = null
+    for(value in this) {
+        if (minValue == null || value.compareTo(minValue!!) < 0) {
+            minValue = value
+        }
+    }
+    return minValue
+}
+
+fun box() : String {
+    val users = arrayListOf(
+            User("John", "Doe", 30),
+            User("Jane", "Doe", 27))
+
+    val ages = users.map { it.age }
+
+    val minAge = ages.testMin()
+    return if (minAge == 27) "OK" else "fail"
+}