Implement the function.sent proposal.

src/parsing/parser.cc

 // 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.
 
 #include "src/parsing/parser.h"
 
 #include "src/api.h"
 #include "src/ast/ast.h"
 #include "src/ast/ast-expression-rewriter.h"
 #include "src/ast/ast-expression-visitor.h"
@@ skipping 625 matching lines @@
                                               int pos) {
   static const int kNewTargetStringLength = 10;
   auto proxy = scope->NewUnresolved(
       factory, parser_->ast_value_factory()->new_target_string(),
       Variable::NORMAL, pos, pos + kNewTargetStringLength);
   proxy->set_is_new_target();
   return proxy;
 }
 
 
+Expression* ParserTraits::FunctionSentExpression(Scope* scope,
+                                                 AstNodeFactory* factory,
+                                                 int pos) {
+  // We desugar function.sent into %GeneratorGetInput(generator).
+  Zone* zone = parser_->zone();
+  ZoneList<Expression*>* args = new (zone) ZoneList<Expression*>(1, zone);
+  VariableProxy* generator = factory->NewVariableProxy(
+      parser_->function_state_->generator_object_variable());
+  args->Add(generator, zone);
+  return factory->NewCallRuntime(Runtime::kGeneratorGetInput, args, pos);
+}
+
+
 Expression* ParserTraits::DefaultConstructor(bool call_super, Scope* scope,
                                              int pos, int end_pos,
                                              LanguageMode mode) {
   return parser_->DefaultConstructor(call_super, scope, pos, end_pos, mode);
 }
 
 
 Literal* ParserTraits::ExpressionFromLiteral(Token::Value token, int pos,
                                              Scanner* scanner,
                                              AstNodeFactory* factory) {
@@ skipping 5117 matching lines @@
     auto class_literal = value->AsClassLiteral();
     if (class_literal->raw_name() == nullptr) {
       class_literal->set_raw_name(name);
     }
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8