Refactor ClassGenTest

Initialize environment with JDK_ONLY in setUp(), allowing to quickly launch
tests without compilation of stdlib.

Remove duplicate/unneeded/commented out tests

compiler/testData/codegen/regressions/kt1120.kt

@@ -1,23 +1,14 @@
-import java.util.concurrent.ConcurrentLinkedQueue
-
-public object RefreshQueue {
-    private val queue = ConcurrentLinkedQueue<List<String>>
-
-    private val workerThread = Thread(object : Runnable {
+object RefreshQueue {
+    val workerThread: Thread = Thread(object : Runnable {
         override fun run() {
-                while (!workerThread.isInterrupted()) {
-                    try {
-//                        synchronized(queue) {
-//                            queue.wait()
-//                        }
-                    } catch (e : InterruptedException) {
-                    }
-                }
+            val a = workerThread
+            val b = RefreshQueue.workerThread
+            if (a != b) throw AssertionError()
         }
     })
 }
 
 fun box() : String {
-    val t = RefreshQueue.workerThread
+    RefreshQueue.workerThread.run()
     return "OK"
-}
+}

compiler/testData/codegen/regressions/kt1538.kt

@@ -1,5 +1,7 @@
 import java.util.HashMap
 
+data class Pair<First, Second>(val first: First, val second: Second)
+
 fun parseCatalogs(hashMap: Any?) {
     val r = toHasMap(hashMap)
     if (!r.first) {

compiler/testData/codegen/regressions/kt285.jet

@@ -1,17 +1,12 @@
-class SimpleClass() : java.lang.Object() {
-    fun foo() : String = "610" + toString ()
-
-    override fun toString() : String { return foo() }
+trait Trait {
+    fun foo() = "O"
+    fun toString() = "K"
 }
 
-class ComplexClass() : SimpleClass by delegate {
-    val delegate = SimpleClass()
-    override fun toString() : String { return foo() + " complex" }
+class SimpleClass : Trait
+
+class ComplexClass : Trait by SimpleClass() {
+    override fun toString() = foo() + super.toString()
 }
 
-fun box() : String {
-  val c = SimpleClass()
-  val d = ComplexClass()
-  System.out?.println(d)
-  return c.foo()
-}
+fun box() = ComplexClass().toString()

compiler/testData/codegen/regressions/kt694.jet

@@ -1,9 +0,0 @@
-package org2
-
-enum class Test {
-    A
-    B
-    C
-}
-
-fun box() = Test.A.toString()

compiler/testData/codegen/regressions/kt857.jet

@@ -1,7 +0,0 @@
-package container_test
-
-class Container<T>(var t : T) {
-    fun getT() : T = t
-}
-
-fun box() = Container<String>("OK").getT()