[JS IR] switch to the IC Ir2Js and fix tests

js/js.translator/testData/box/escapedIdentifiers/classLikeMemberClassMangling.kt

@@ -16,8 +16,13 @@ fun box(): String {
     // DCE preventing
     val b = B()
 
-    assertEquals("function", js("typeof A['\$invalid inner']"))
-    assertEquals(js("undefined"), js("B['\$invalid inner']"))
+    val aCtor = A::class.js.asDynamic()
+    val bCtor = B::class.js.asDynamic()
+
+    assertEquals("function", typeOf(aCtor["\$invalid inner"]))
+    assertEquals(js("undefined"), bCtor["\$invalid inner"])
 
     return "OK"
-}
+}
+
+private fun typeOf(t: Any): String = js("typeof t")

js/js.translator/testData/box/jsName/jsNamePropertyAccessors.kt

@@ -1,5 +1,4 @@
 // EXPECTED_REACHABLE_NODES: 1285
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
 package foo