Scanner: remove PushBack calls when we're going to return ILLEGAL.

test/cctest/test-parsing.cc

Index: test/cctest/test-parsing.cc
diff --git a/test/cctest/test-parsing.cc b/test/cctest/test-parsing.cc
index e45e9ebb892c7499b6808296eb6166b00c4ed58d..b9adb17bb95851d6e35bf3c6bba6e58d1a8f8a40 100644
--- a/test/cctest/test-parsing.cc
+++ b/test/cctest/test-parsing.cc
@@ -4253,3 +4253,17 @@ TEST(ConstParsingInForInError) {
   RunParserSyncTest(context_data, data, kError, NULL, 0, always_flags,
                     arraysize(always_flags));
 }
+
+
+TEST(InvalidUnicodeEscapes) {
+  const char* context_data[][2] = {{"", ""},
+                                   {"'use strict';", ""},
+                                   {NULL, NULL}};
+  const char* data[] = {
+    "var foob\\u123r = 0;",
+    "var \\u123roo = 0;",
+    "\"foob\\u123rr\"",
+    "/regex/g\\u123r",
+    NULL};
+  RunParserSyncTest(context_data, data, kError);
+}