Implement the function.sent proposal.

src/parsing/parser.h

 // Copyright 2012 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_PARSING_PARSER_H_
 #define V8_PARSING_PARSER_H_
 
 #include "src/allocation.h"
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
@@ skipping 495 matching lines @@
   const AstRawString* GetNumberAsSymbol(Scanner* scanner);
 
   Expression* ThisExpression(Scope* scope, AstNodeFactory* factory,
                              int pos = RelocInfo::kNoPosition);
   Expression* SuperPropertyReference(Scope* scope, AstNodeFactory* factory,
                                      int pos);
   Expression* SuperCallReference(Scope* scope, AstNodeFactory* factory,
                                  int pos);
   Expression* NewTargetExpression(Scope* scope, AstNodeFactory* factory,
                                   int pos);
+  Expression* FunctionSentExpression(Scope* scope, AstNodeFactory* factory,
+                                     int pos);
   Expression* DefaultConstructor(bool call_super, Scope* scope, int pos,
                                  int end_pos, LanguageMode language_mode);
   Literal* ExpressionFromLiteral(Token::Value token, int pos, Scanner* scanner,
                                  AstNodeFactory* factory);
   Expression* ExpressionFromIdentifier(const AstRawString* name,
                                        int start_position, int end_position,
                                        Scope* scope, AstNodeFactory* factory);
   Expression* ExpressionFromString(int pos, Scanner* scanner,
                                    AstNodeFactory* factory);
   Expression* GetIterator(Expression* iterable, AstNodeFactory* factory,
@@ skipping 685 matching lines @@
 
 DoExpression* ParserTraits::ParseDoExpression(bool* ok) {
   return parser_->ParseDoExpression(ok);
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_H_