[debugger] step-next across yield should not leave the generator.

src/runtime/runtime-debug.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/debug/debug-evaluate.h"
 #include "src/debug/debug-frames.h"
 #include "src/debug/debug-scopes.h"
@@ skipping 1854 matching lines @@
 }
 
 // Set one shot breakpoints for the suspended generator object.
 RUNTIME_FUNCTION(Runtime_DebugPrepareStepInSuspendedGenerator) {
   HandleScope scope(isolate);
   DCHECK_EQ(0, args.length());
   isolate->debug()->PrepareStepInSuspendedGenerator();
   return isolate->heap()->undefined_value();
 }
 
-RUNTIME_FUNCTION(Runtime_DebugRecordAsyncFunction) {
+RUNTIME_FUNCTION(Runtime_DebugRecordGenerator) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0);
   CHECK(isolate->debug()->last_step_action() >= StepNext);
-  isolate->debug()->RecordAsyncFunction(generator);
+  isolate->debug()->RecordGenerator(generator);
   return isolate->heap()->undefined_value();
 }
 
 RUNTIME_FUNCTION(Runtime_DebugPushPromise) {
   DCHECK(args.length() == 1);
   HandleScope scope(isolate);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, promise, 0);
   isolate->PushPromise(promise);
   return isolate->heap()->undefined_value();
 }
@@ skipping 29 matching lines @@
 }
 
 
 RUNTIME_FUNCTION(Runtime_DebugBreakInOptimizedCode) {
   UNIMPLEMENTED();
   return NULL;
 }
 
 }  // namespace internal
 }  // namespace v8