Add CoreClasses

pkg/compiler/lib/src/ssa/nodes.dart

Index: pkg/compiler/lib/src/ssa/nodes.dart
diff --git a/pkg/compiler/lib/src/ssa/nodes.dart b/pkg/compiler/lib/src/ssa/nodes.dart
index 08f69873a35bfdb63e4ab22639011347ea512d95..e3a719de4d29df74b12f1a5b5f69478ff49c6804 100644
--- a/pkg/compiler/lib/src/ssa/nodes.dart
+++ b/pkg/compiler/lib/src/ssa/nodes.dart
@@ -1319,9 +1319,9 @@ abstract class HInstruction implements Spannable {
     assert(type.kind != TypeKind.TYPE_VARIABLE);
     assert(type.treatAsRaw || type.isFunctionType);
     if (type.isDynamic) return this;
+    if (type.isObject) return this;
     // The type element is either a class or the void element.
     Element element = type.element;
-    if (identical(element, compiler.objectClass)) return this;
     JavaScriptBackend backend = compiler.backend;
     if (type.kind != TypeKind.INTERFACE) {
       return new HTypeConversion(type, kind, backend.dynamicType, this);