Implement ES6 completion semantics (--harmony-completion).

src/parser.cc

Index: src/parser.cc
diff --git a/src/parser.cc b/src/parser.cc
index e3ce0f0172a4c340c0a904d30c6511b7b9bb476a..83492a02a5ff86c83fb4d4cf01530dfe4e4a5dc1 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -3327,7 +3327,7 @@ Statement* Parser::DesugarLexicalBindingsInForStatement(
     Scope* inner_scope, bool is_const, ZoneList<const AstRawString*>* names,
     ForStatement* loop, Statement* init, Expression* cond, Statement* next,
     Statement* body, bool* ok) {
-  // ES6 13.6.3.4 specifies that on each loop iteration the let variables are
+  // ES6 13.7.4.8 specifies that on each loop iteration the let variables are
   // copied into a new environment. After copying, the "next" statement of the
   // loop is executed to update the loop variables. The loop condition is
   // checked and the loop body is executed.
@@ -3364,7 +3364,7 @@ Statement* Parser::DesugarLexicalBindingsInForStatement(
   //          break outer;
   //        }
   //      }
-  //      if (flag == 1) {
+  //      if (flag == 1) {  // Body used break.
   //        break;
   //      }
   //    }