[parser] Fix declaration order of "arguments" and func name.

They were in the wrong order in PreParser, which caused problem for "function
arguments() { ... }".

BUG=chromium:801772

Change-Id: Ia04c8c8c0a5d641fd1db0746dc3312c83ebcaf24
Reviewed-on: https://chromium-review.googlesource.com/865900Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50640}

src/parsing/preparser.cc

@@ -207,12 +207,12 @@ PreParser::PreParseResult PreParser::PreParseFunction(
 
   if (!IsArrowFunction(kind) && track_unresolved_variables_ &&
       result == kLazyParsingComplete) {
-    DeclareFunctionNameVar(function_name, function_type, function_scope);
-
     // Declare arguments after parsing the function since lexical 'arguments'
     // masks the arguments object. Declare arguments before declaring the
     // function var since the arguments object masks 'function arguments'.
     function_scope->DeclareArguments(ast_value_factory());
+
+    DeclareFunctionNameVar(function_name, function_type, function_scope);
   }
 
   use_counts_ = nullptr;

test/mjsunit/regress/regress-801772.js

+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+function foo(f) { f(); }
+
+foo(function arguments() {
+    function skippable() { }
+});