Replaced when appropriate 'TARGET_BACKEND: JVM' -> 'IGNORE_BACKEND: JS'. Enabled some succesfully working decompiledText tests.

compiler/testData/codegen/box/classes/classObjectToString.kt

@@ -1,5 +1,5 @@
 // TODO: Enable for JS when it supports Java class library.
-// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JS
 class SomeClass { companion object }
 
 fun box() = 

compiler/testData/codegen/box/classes/delegationJava.kt

@@ -1,5 +1,5 @@
 // Enable for JS when it supports Java class library.
-// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JS
 
 class TestJava(r : Runnable) : Runnable by r {}
 class TestRunnable() : Runnable {

compiler/testData/codegen/box/classes/kt1120.kt

@@ -1,6 +1,6 @@
 // Won't ever work with JS backend.
 // TODO: Consider rewriting this test without using threads, since the issue is not about threads at all.
-// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JS
 
 object RefreshQueue {
     val any = Any()

compiler/testData/codegen/box/classes/kt1134.kt

@@ -1,5 +1,5 @@
 // TODO: Enable when JS backend supports Java class library
-// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JS
 public class SomeClass() : java.lang.Object() {
 }
 

compiler/testData/codegen/box/classes/kt1535.kt

@@ -1,5 +1,5 @@
 // TODO: Enable when JS backend supports Java class library, since FunctionX are required for interoperation
-// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JS
 class Works() : Function0<Any> {
     public override fun invoke():Any {
       return "Works" as Any

compiler/testData/codegen/box/classes/kt2288.kt

@@ -1,5 +1,5 @@
 // TODO: Enable when JS backend supports Java class library
-// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JS
 public open class Test(): java.util.RandomAccess, Cloneable, java.io.Serializable
 {
         public override fun clone(): Test = Test() // Override 'clone()' with more precise type 'Test'

compiler/testData/codegen/box/classes/kt2395.kt

@@ -1,5 +1,5 @@
 // TODO: Enable when JS backend supports Java class library
-// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JS
 import java.util.AbstractList
 
 class MyList(): AbstractList<String>() {

compiler/testData/codegen/box/classes/kt508.kt

@@ -1,5 +1,5 @@
 // TODO: Enable for JS when it supports Java class library.
-// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JS
 import java.util.HashMap
 import java.io.*
 

compiler/testData/codegen/box/classes/kt707.kt

@@ -1,5 +1,5 @@
 // TODO: Enable for JS when it supports Java class library.
-// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JS
 class List<T>(val head: T, val tail: List<T>? = null)
 
 fun <T> List<T>.mapHead(f: (T)-> T): List<T> = List<T>(f(head), null)