Move closing of generators upon final return to the generator-resume builtin.

src/interpreter/bytecode-generator.cc

Index: src/interpreter/bytecode-generator.cc
diff --git a/src/interpreter/bytecode-generator.cc b/src/interpreter/bytecode-generator.cc
index a011ead6433489d02aa8a8e5e3ec93655ba64c01..fa685f62466f0aeee9cb47ffcf0091f01d18ec20 100644
--- a/src/interpreter/bytecode-generator.cc
+++ b/src/interpreter/bytecode-generator.cc
@@ -2249,8 +2249,10 @@ void BytecodeGenerator::BuildReturn() {
   if (info()->literal()->feedback_vector_spec()->HasTypeProfileSlot()) {
     builder()->CollectTypeProfile(info()->literal()->return_position());
   }
-  if (IsGeneratorFunction(info()->literal()->kind())) {
-    // Mark the generator as closed if returning from a generator function.
+  if (IsAsyncGeneratorFunction(info()->literal()->kind())) {
+    // Mark the generator as closed if returning from an async generator
+    // function. Note that non-async generators are closed by the
+    // generator-resume builtin.

[rmcilroy, 2017/06/13 12:36:00]

I'm guessing you could do this for async generators too? Can you add a TODO here
to move closing of async generators too.

     RegisterAllocationScope register_scope(this);
     Register result = register_allocator()->NewRegister();
     builder()