[turbofan] [deoptimizer] Support inlining of ES6 tail calls.

src/runtime/runtime-compiler.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/compiler.h"
 #include "src/deoptimizer.h"
 #include "src/frames-inl.h"
@@ skipping 104 matching lines @@
   Handle<Code> optimized_code = deoptimizer->compiled_code();
 
   DCHECK(optimized_code->kind() == Code::OPTIMIZED_FUNCTION);
   DCHECK(type == deoptimizer->bailout_type());
 
   // Make sure to materialize objects before causing any allocation.
   JavaScriptFrameIterator it(isolate);
   deoptimizer->MaterializeHeapObjects(&it);
   delete deoptimizer;
 
-  JavaScriptFrame* frame = it.frame();
-  RUNTIME_ASSERT(frame->function()->IsJSFunction());
-  DCHECK(frame->function() == *function);
-
   // Ensure the context register is updated for materialized objects.
   JavaScriptFrameIterator top_it(isolate);
   JavaScriptFrame* top_frame = top_it.frame();
   isolate->set_context(Context::cast(top_frame->context()));
 
   if (type == Deoptimizer::LAZY) {
     return isolate->heap()->undefined_value();
   }
 
-  // Search for other activations of the same function and code.
+  // Search for other activations of the same optimized code.
+  // At this point {it} is at the topmost frame of all the frames materialized
+  // by the deoptimizer. Note that this frame does not necessarily represent
+  // an activation of {function} because of potential inlined tail-calls.
   ActivationsFinder activations_finder(*optimized_code);
   activations_finder.VisitFrames(&it);
   isolate->thread_manager()->IterateArchivedThreads(&activations_finder);
 
   if (!activations_finder.has_code_activations_) {
     if (function->code() == *optimized_code) {
       if (FLAG_trace_deopt) {
         PrintF("[removing optimized code for: ");
         function->PrintName();
         PrintF("]\n");
@@ skipping 211 matching lines @@
   DCHECK(is_valid_language_mode(args.smi_at(3)));
   LanguageMode language_mode = static_cast<LanguageMode>(args.smi_at(3));
   DCHECK(args[4]->IsSmi());
   Handle<SharedFunctionInfo> outer_info(args.at<JSFunction>(2)->shared(),
                                         isolate);
   return CompileGlobalEval(isolate, args.at<String>(1), outer_info,
                            language_mode, args.smi_at(4));
 }
 }  // namespace internal
 }  // namespace v8