Raise deprecation level for jsClass functions

Suppress error in tests

#KT-21703

js/js.translator/testData/box/reflection/jsClass.kt

@@ -1,6 +1,7 @@
 // EXPECTED_REACHABLE_NODES: 1169
 package foo
 
+@Suppress("DEPRECATION_ERROR")
 fun box(): String {
     check(jsClass<A>(), A().jsClass)
     check(jsClass<B>(), B().jsClass)

js/js.translator/testData/box/reflection/jsClassName.kt

@@ -2,6 +2,7 @@
 // EXPECTED_REACHABLE_NODES: 1174
 package foo
 
+@Suppress("DEPRECATION_ERROR")
 fun testWithInstance() {
     assertEquals("A", A().jsClass.name)
     assertEquals("B", B().jsClass.name)
@@ -13,6 +14,7 @@ fun testWithInstance() {
     assertEquals("R", R().jsClass.name)
 }
 
+@Suppress("DEPRECATION_ERROR")
 fun testWithClassReference() {
     assertEquals("A", jsClass<A>().name)
     assertEquals("B", jsClass<B>().name)

js/js.translator/testData/box/reflection/jsClassOnReifiedType.kt

@@ -1,11 +1,13 @@
 // EXPECTED_REACHABLE_NODES: 1165
 package foo
 
+@Suppress("DEPRECATION_ERROR")
 inline fun <reified T : Any> foo(): JsClass<T> {
     val T = 1
     return jsClass<T>()
 }
 
+@Suppress("DEPRECATION_ERROR")
 fun box(): String {
     check(jsClass<A>(), foo<A>())
     check(jsClass<B>(), foo<B>())

js/js.translator/testData/box/reflection/jsClassOnReifiedTypeInLambda.kt

@@ -2,11 +2,13 @@
 // EXPECTED_REACHABLE_NODES: 1167
 package foo
 
+@Suppress("DEPRECATION_ERROR")
 inline fun <reified T : Any> foo(): () -> JsClass<T> {
     val T = 1
     return { jsClass<T>() }
 }
 
+@Suppress("DEPRECATION_ERROR")
 fun box(): String {
     check(jsClass<A>(), foo<A>()())
     check(jsClass<B>(), foo<B>()())

js/js.translator/testData/box/reflection/jsClassSimpleName.kt

@@ -9,6 +9,7 @@ class Outer {
     inner class Inner
 }
 
+@Suppress("DEPRECATION_ERROR")
 fun testWithInstance() {
     assertEquals("A", A().jsClass.simpleName)
     assertEquals("B", B().jsClass.simpleName)
@@ -22,6 +23,7 @@ fun testWithInstance() {
     assertEquals("Inner", Outer().Inner().jsClass.simpleName)
 }
 
+@Suppress("DEPRECATION_ERROR")
 fun testWithClassReference() {
     assertEquals("A", jsClass<A>().simpleName)
     assertEquals("B", jsClass<B>().simpleName)

libraries/stdlib/js/src/kotlin/reflect/JsClass.kt

@@ -19,10 +19,10 @@ external interface JsClass<T : Any> {
     val name: String
 }
 
-@Deprecated("Use class literal and extension property `js` instead.", replaceWith = ReplaceWith("T::class.js"), level = DeprecationLevel.WARNING)
+@Deprecated("Use class literal and extension property `js` instead.", replaceWith = ReplaceWith("T::class.js"), level = DeprecationLevel.ERROR)
 external fun <T : Any> jsClass(): JsClass<T>
 
-@Deprecated("Use class literal and extension property `js` instead.", replaceWith = ReplaceWith("this::class.js"), level = DeprecationLevel.WARNING)
+@Deprecated("Use class literal and extension property `js` instead.", replaceWith = ReplaceWith("this::class.js"), level = DeprecationLevel.ERROR)
 val <T : Any> T.jsClass: JsClass<T>
     get() = when (jsTypeOf(this)) {
         "string" -> js("String")