Revert of Replace all remaining Oddball checks with new function

src/ast/ast.cc

Index: src/ast/ast.cc
diff --git a/src/ast/ast.cc b/src/ast/ast.cc
index 27e325fb1e8c134c17392cbfc642e63ccef2b781..a943fdf05cafd437e75ce5ab1524365569d4227a 100644
--- a/src/ast/ast.cc
+++ b/src/ast/ast.cc
@@ -59,19 +59,12 @@
 
 
 bool Expression::IsNullLiteral() const {
-  if (!IsLiteral()) return false;
-  Handle<Object> value = AsLiteral()->value();
-  return !value->IsSmi() &&
-         value->IsNull(HeapObject::cast(*value)->GetIsolate());
+  return IsLiteral() && AsLiteral()->value()->IsNull();
 }
 
 bool Expression::IsUndefinedLiteral() const {
-  if (IsLiteral()) {
-    Handle<Object> value = AsLiteral()->value();
-    if (!value->IsSmi() &&
-        value->IsUndefined(HeapObject::cast(*value)->GetIsolate())) {
-      return true;
-    }
+  if (IsLiteral() && AsLiteral()->value()->IsUndefined()) {
+    return true;
   }
 
   const VariableProxy* var_proxy = AsVariableProxy();
@@ -394,7 +387,7 @@
     if (property->is_computed_name()) continue;
     if (property->kind() == ObjectLiteral::Property::PROTOTYPE) continue;
     Literal* literal = property->key()->AsLiteral();
-    DCHECK(!literal->IsNullLiteral());
+    DCHECK(!literal->value()->IsNull());
 
     // If there is an existing entry do not emit a store unless the previous
     // entry was also an accessor.
@@ -464,11 +457,11 @@
     // (value->IsNumber()).
     // TODO(verwaest): Remove once we can store them inline.
     if (FLAG_track_double_fields &&
-        (value->IsNumber() || value->IsUninitialized(isolate))) {
+        (value->IsNumber() || value->IsUninitialized())) {
       may_store_doubles_ = true;
     }
 
-    is_simple = is_simple && !value->IsUninitialized(isolate);
+    is_simple = is_simple && !value->IsUninitialized();
 
     // Keep track of the number of elements in the object literal and
     // the largest element index.  If the largest element index is
@@ -536,7 +529,7 @@
       continue;
     }
 
-    if (boilerplate_value->IsUninitialized(isolate)) {
+    if (boilerplate_value->IsUninitialized()) {
       boilerplate_value = handle(Smi::FromInt(0), isolate);
       is_simple = false;
     }