Raise deprecation level for jsClass functions

Suppress error in tests

#KT-21703

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)