[x86] Faster/shorter code for stack checks.

src/compiler/instruction-selector.h

 // 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.
 
 #ifndef V8_COMPILER_INSTRUCTION_SELECTOR_H_
 #define V8_COMPILER_INSTRUCTION_SELECTOR_H_
 
 #include <map>
 
 #include "src/compiler/common-operator.h"
@@ skipping 111 matching lines @@
   // Checks if {node} has any uses, and therefore code has to be generated for
   // it.
   bool IsUsed(Node* node) const;
 
   // Checks if {node} is currently live.
   bool IsLive(Node* node) const { return !IsDefined(node) && IsUsed(node); }
 
   int GetVirtualRegister(const Node* node);
   const std::map<NodeId, int> GetVirtualRegistersForTesting() const;
 
+  Isolate* isolate() const { return sequence()->isolate(); }
+
  private:
   friend class OperandGenerator;
 
   // Inform the instruction selection that {node} was just defined.
   void MarkAsDefined(Node* node);
 
   // Inform the instruction selection that {node} has at least one use and we
   // will need to generate code for it.
   void MarkAsUsed(Node* node);
 
@@ skipping 88 matching lines @@
   BoolVector defined_;
   BoolVector used_;
   IntVector virtual_registers_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_SELECTOR_H_