[es7] implement |do| expressions proposal

src/rewriter.h

Index: src/rewriter.h
diff --git a/src/rewriter.h b/src/rewriter.h
index 4e76cd64c4ade13b68026a0f37b1f43fd5587551..fdb36d1d3e20773fd28557766a5f5f833127d314 100644
--- a/src/rewriter.h
+++ b/src/rewriter.h
@@ -8,7 +8,10 @@
 namespace v8 {
 namespace internal {
 
+class AstValueFactory;
+class DoExpression;
 class ParseInfo;
+class Parser;
 
 class Rewriter {
  public:
@@ -19,6 +22,11 @@ class Rewriter {
   // Assumes code has been parsed and scopes have been analyzed.  Mutates the
   // AST, so the AST should not continue to be used in the case of failure.
   static bool Rewrite(ParseInfo* info);
+
+  // Rewrite a list of statements, using the same rules as a top-level program,
+  // to  ensure identical behaviour of completion result.
+  static bool Rewrite(Parser* parser, DoExpression* expr,
+                      AstValueFactory* factory);
 };