[Interpreter] Add support for global declarations and load/store of global variables

src/interpreter/bytecode-generator.h

 // Copyright 2015 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_INTERPRETER_BYTECODE_GENERATOR_H_
 #define V8_INTERPRETER_BYTECODE_GENERATOR_H_
 
 #include "src/ast.h"
 #include "src/interpreter/bytecode-array-builder.h"
 #include "src/interpreter/bytecodes.h"
 
 namespace v8 {
 namespace internal {
 namespace interpreter {
 
 class BytecodeGenerator : public AstVisitor {
  public:
   BytecodeGenerator(Isolate* isolate, Zone* zone);
   virtual ~BytecodeGenerator();
 
   Handle<BytecodeArray> MakeBytecode(CompilationInfo* info);
 
 #define DECLARE_VISIT(type) void Visit##type(type* node) override;
   AST_NODE_LIST(DECLARE_VISIT)
 #undef DECLARE_VISIT
 
+  // Visiting function for declarations list is overridden.
+  void VisitDeclarations(ZoneList<Declaration*>* declarations) override;
+
  private:
   DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
 
   void VisitArithmeticExpression(BinaryOperation* binop);
   void VisitPropertyLoad(Register obj, Property* expr);
-  void VisitVariableLoad(Variable* variable);
+  void VisitVariableLoad(Variable* variable, FeedbackVectorICSlot slot);
+  void VisitVariableAssignment(Variable* variable, FeedbackVectorICSlot slot);
 
   inline BytecodeArrayBuilder& builder() { return builder_; }
   inline Scope* scope() const { return scope_; }
   inline void set_scope(Scope* scope) { scope_ = scope; }
   inline CompilationInfo* info() const { return info_; }
   inline void set_info(CompilationInfo* info) { info_ = info; }
+  ZoneVector<Handle<Object>>* globals() { return &globals_; }
 
   LanguageMode language_mode() const;
   int feedback_index(FeedbackVectorICSlot slot) const;
+  Register current_context() const;
 
   BytecodeArrayBuilder builder_;
   CompilationInfo* info_;
   Scope* scope_;
+  ZoneVector<Handle<Object>> globals_;
+
+  // TODO(rmcilroy): Encapsulate this in an environment object.
+  Register current_context_;
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_GENERATOR_H_