Calling a generator function returns a generator object

src/objects-debug.cc

Index: src/objects-debug.cc
diff --git a/src/objects-debug.cc b/src/objects-debug.cc
index 44cab53cc7ae90696e7c34929084e0e6e1e318bd..69cd2cf6a49e72e9acbc5fb6c2309de3088a10a0 100644
--- a/src/objects-debug.cc
+++ b/src/objects-debug.cc
@@ -139,6 +139,9 @@ void HeapObject::HeapObjectVerify() {
     case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
       JSObject::cast(this)->JSObjectVerify();
       break;
+    case JS_GENERATOR_ITERATOR_TYPE:
+      JSGeneratorIterator::cast(this)->JSGeneratorIteratorVerify();
+      break;
     case JS_MODULE_TYPE:
       JSModule::cast(this)->JSModuleVerify();
       break;
@@ -404,6 +407,17 @@ void FixedDoubleArray::FixedDoubleArrayVerify() {
 }
 
 
+void JSGeneratorIterator::JSGeneratorIteratorVerify() {
+  VerifyObjectField(kFunctionOffset);
+  VerifyObjectField(kContextOffset);
+  CHECK(context() == Smi::FromInt(0) || context()->IsContext());
+  VerifySmiField(kContinuationOffset);
+  CHECK_GE(continuation(), 0);
+  VerifyObjectField(kOperandStackOffset);
+  CHECK(operand_stack() == Smi::FromInt(0) || operand_stack()->IsFixedArray());
+}
+
+
 void JSModule::JSModuleVerify() {
   VerifyObjectField(kContextOffset);
   VerifyObjectField(kScopeInfoOffset);