[Interpreter] Ensure StackCheck bytecode handler is in split-edge form.

src/compiler/raw-machine-assembler.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/compiler/raw-machine-assembler.h"
 
 #include "src/code-factory.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/pipeline.h"
 #include "src/compiler/scheduler.h"
@@ skipping 34 matching lines @@
   schedule_ = nullptr;
   return schedule;
 }
 
 
 Node* RawMachineAssembler::Parameter(size_t index) {
   DCHECK(index < parameter_count());
   return parameters_[index];
 }
 
+void RawMachineAssembler::Fallthrough(RawMachineLabel* label) {
+  DCHECK(current_block_ != schedule()->end());
+  RawMachineLabel fallthrough;
+
+  // This Goto dance ensures we remain in split-edge form.
+  Goto(&fallthrough);
+  Bind(label);
+  Goto(&fallthrough);
+  Bind(&fallthrough);
+}
 
 void RawMachineAssembler::Goto(RawMachineLabel* label) {
   DCHECK(current_block_ != schedule()->end());
   schedule()->AddGoto(CurrentBlock(), Use(label));
   current_block_ = nullptr;
 }
 
 
 void RawMachineAssembler::Branch(Node* condition, RawMachineLabel* true_val,
                                  RawMachineLabel* false_val) {
@@ skipping 397 matching lines @@
 
 RawMachineLabel::RawMachineLabel()
     : block_(nullptr), used_(false), bound_(false) {}
 
 
 RawMachineLabel::~RawMachineLabel() { DCHECK(bound_ || !used_); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8