Do not reference java.util in tests that run on JS backend.

compiler/testData/codegen/box/when/is.kt

@@ -1,11 +1,11 @@
 fun typeName(a: Any?) : String {
     return when(a) {
-        is java.util.ArrayList<*> -> "array list"
+        is ArrayList<*> -> "array list"
         else -> "no idea"
     }
 }
 
 fun box() : String {
-    if(typeName(java.util.ArrayList<Int> ()) != "array list") return "array list failed"
+    if(typeName(ArrayList<Int>()) != "array list") return "array list failed"
     return "OK"
 }

compiler/testData/codegen/box/when/range.kt

@@ -1,5 +1,5 @@
 fun isDigit(a: Int) : String {
-    val aa = java.util.ArrayList<Int> ()
+    val aa = ArrayList<Int> ()
     aa.add(239)
 
     return when(a) {

compiler/testData/codegen/box/when/switchOptimizationDense.kt

@@ -1,7 +1,5 @@
 // WITH_RUNTIME
 
-import java.util.ArrayList
-
 fun dense(x: Int): Int {
     return when (x) {
         -4 -> 9

compiler/testData/codegen/box/when/switchOptimizationSparse.kt

@@ -1,7 +1,5 @@
 // WITH_RUNTIME
 
-import java.util.ArrayList
-
 fun sparse(x: Int): Int {
     return when ((x % 4) * 100) {
         100 -> 1

compiler/testData/codegen/box/when/whenArgumentIsEvaluatedOnlyOnce.kt

@@ -4,7 +4,7 @@ fun inc(): Int {
     return 0
 }
 fun box(): String {
-  val al = java.util.ArrayList<Int>()
+  val al = ArrayList<Int>()
   when (inc()) {
       in al -> return "fail 1"
       else -> {}