Adjust testData: JDK collections behave like non-platform in backend

Some of that changes looks like regression and should be fixed soon

compiler/testData/codegen/box/platformTypes/primitives/identityEquals.kt

@@ -3,7 +3,7 @@ fun box(): String {
     l.add(1000)
 
     val x = l[0] === 1000
-    if (x) return "Fail: $x"
+    if (!x) return "Fail: $x"
     val x1 = l[0] === 1
     if (x1) return "Fail 1: $x"
     val x2 = l[0] === l[0]

compiler/testData/codegen/boxWithStdlib/fullJdk/platformTypeAssertionStackTrace.kt

@@ -1,8 +1,7 @@
-import java.util.Arrays
-import java.util.ArrayList
+import java.util.*
 
 fun box(): String {
-    val a = ArrayList<String>()
+    val a = ArrayList<String>() as AbstractList<String>
     a.add(null)
     try {
         val b: String = a[0]