Sloppy-mode let parsing

src/preparser.cc

Index: src/preparser.cc
diff --git a/src/preparser.cc b/src/preparser.cc
index ec0ea2de3a04ba42bf5b32a54722420fb33de5d7..2feb99e1af3cd9d9a40d124f4336cd0290c82cf9 100644
--- a/src/preparser.cc
+++ b/src/preparser.cc
@@ -198,7 +198,7 @@ PreParser::Statement PreParser::ParseStatementListItem(bool* ok) {
       }
       break;
     case Token::LET:
-      if (allow_let()) {
+      if (IsLetKeyword()) {
         return ParseVariableStatement(kStatementListItem, ok);
       }
       break;
@@ -874,7 +874,7 @@ PreParser::Statement PreParser::ParseForStatement(bool* ok) {
   if (peek() != Token::SEMICOLON) {
     ForEachStatement::VisitMode mode;
     if (peek() == Token::VAR || (peek() == Token::CONST && allow_const()) ||
-        (peek() == Token::LET && allow_let())) {
+        (peek() == Token::LET && IsLetKeyword())) {
       int decl_count;
       Scanner::Location first_initializer_loc = Scanner::Location::invalid();
       Scanner::Location bindings_loc = Scanner::Location::invalid();