[turbofan] Support initial step-in through debugger statement.

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/v8.h"
 
 #include "src/accessors.h"
 #include "src/arguments.h"
 #include "src/compiler.h"
 #include "src/debug.h"
@@ skipping 1534 matching lines @@
   CONVERT_NUMBER_CHECKED(int, break_id, Int32, args[0]);
   RUNTIME_ASSERT(isolate->debug()->CheckExecutionState(break_id));
 
   CONVERT_SMI_ARG_CHECKED(wrapped_id, 1);
 
   // Get the frame where the debugging is performed.
   StackFrame::Id id = UnwrapFrameId(wrapped_id);
   JavaScriptFrameIterator frame_it(isolate, id);
   RUNTIME_ASSERT(!frame_it.done());
 
-  JavaScriptFrame* frame = frame_it.frame();
+  List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
+  frame_it.frame()->Summarize(&frames);
+  FrameSummary summary = frames.first();
 
-  Handle<JSFunction> fun = Handle<JSFunction>(frame->function());
+  Handle<JSFunction> fun = Handle<JSFunction>(summary.function());
   Handle<SharedFunctionInfo> shared = Handle<SharedFunctionInfo>(fun->shared());
 
   if (!isolate->debug()->EnsureDebugInfo(shared, fun)) {
     return isolate->heap()->undefined_value();
   }
 
   Handle<DebugInfo> debug_info = Debug::GetDebugInfo(shared);
 
   // Find range of break points starting from the break point where execution
   // has stopped.
-  Address call_pc = frame->pc() - 1;
+  Address call_pc = summary.pc() - 1;
   List<BreakLocation> locations;
   BreakLocation::FromAddressSameStatement(debug_info, ALL_BREAK_LOCATIONS,
                                           call_pc, &locations);
 
   Handle<JSArray> array = isolate->factory()->NewJSArray(locations.length());
 
   int index = 0;
   for (BreakLocation location : locations) {
     bool accept;
-    if (location.pc() > frame->pc()) {
+    if (location.pc() > summary.pc()) {
       accept = true;
     } else {
       StackFrame::Id break_frame_id = isolate->debug()->break_frame_id();
       // The break point is near our pc. Could be a step-in possibility,
       // that is currently taken by active debugger call.
       if (break_frame_id == StackFrame::NO_ID) {
         // We are not stepping.
         accept = false;
       } else {
         JavaScriptFrameIterator additional_frame_it(isolate, break_frame_id);
@@ skipping 1234 matching lines @@
   return Smi::FromInt(isolate->debug()->is_active());
 }
 
 
 RUNTIME_FUNCTION(Runtime_DebugBreakInOptimizedCode) {
   UNIMPLEMENTED();
   return NULL;
 }
 }
 }  // namespace v8::internal