Introduce IsUndefined(Isolate*) and IsTheHole(Isolate*)

src/full-codegen/x64/full-codegen-x64.cc

Index: src/full-codegen/x64/full-codegen-x64.cc
diff --git a/src/full-codegen/x64/full-codegen-x64.cc b/src/full-codegen/x64/full-codegen-x64.cc
index d53f0f19a3e122ce853a127b3f48b549d7f60b06..3cbdaca6fd0585736ca9d869f1551859e7fe6d78 100644
--- a/src/full-codegen/x64/full-codegen-x64.cc
+++ b/src/full-codegen/x64/full-codegen-x64.cc
@@ -504,8 +504,9 @@ void FullCodeGenerator::TestContext::Plug(Handle<Object> lit) const {
                                           true,
                                           true_label_,
                                           false_label_);
-  DCHECK(lit->IsNull() || lit->IsUndefined() || !lit->IsUndetectable());
-  if (lit->IsUndefined() || lit->IsNull() || lit->IsFalse()) {
+  DCHECK(lit->IsNull() || lit->IsUndefined(isolate()) ||
+         !lit->IsUndetectable());
+  if (lit->IsUndefined(isolate()) || lit->IsNull() || lit->IsFalse()) {
     if (false_label_ != fall_through_) __ jmp(false_label_);
   } else if (lit->IsTrue() || lit->IsJSObject()) {
     if (true_label_ != fall_through_) __ jmp(true_label_);