A decimal integer literal with a leading 0 is now an error in strict mode.

src/parsing/preparser.cc

Index: src/parsing/preparser.cc
diff --git a/src/parsing/preparser.cc b/src/parsing/preparser.cc
index 5e87016e16e8211e7f0455fe04966dcb9af21efa..1f4997e7559c0c6f061bf037ff3282b860bed01b 100644
--- a/src/parsing/preparser.cc
+++ b/src/parsing/preparser.cc
@@ -162,8 +162,6 @@ PreParser::PreParseResult PreParser::PreParseFunction(
     if (is_strict(function_scope->language_mode())) {
       int end_pos = scanner()->location().end_pos;
       CheckStrictOctalLiteral(function_scope->start_position(), end_pos, ok);
-      CheckDecimalLiteralWithLeadingZero(function_scope->start_position(),
-                                         end_pos);
     }
   }
   return kPreParseSuccess;
@@ -237,7 +235,6 @@ PreParser::Expression PreParser::ParseFunctionLiteral(
   int end_position = scanner()->location().end_pos;
   if (is_strict(language_mode)) {
     CheckStrictOctalLiteral(start_position, end_position, CHECK_OK);
-    CheckDecimalLiteralWithLeadingZero(start_position, end_position);
   }
   function_scope->set_end_position(end_position);