[parser] Don't mark sloppy block functions as assigned

When preparsing and detecting a sloppy block function redefinition then
don't mark the variable as assigned to make it consistent with the eager
parser.

Bug: chromium:1053364
Change-Id: Iec7c24db80014bfe73ee41a4f3bb7a41a354cef2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2241511
Auto-Submit: Dan Elphick <delphick@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68415}

src/parsing/preparser.cc

@@ -325,10 +325,6 @@ PreParser::Expression PreParser::ParseFunctionLiteral(
     // Parsing the body may change the language mode in our scope.
     language_mode = function_scope->language_mode();
 
-    if (is_sloppy(language_mode)) {
-      function_scope->HoistSloppyBlockFunctions(nullptr);
-    }
-
     // Validate name and parameter names. We can do this only after parsing the
     // function, since the function can declare itself strict.
     CheckFunctionName(language_mode, function_name, function_name_validity,

test/mjsunit/regress/regress-crbug-1053364.js

@@ -0,0 +1,20 @@
+// Copyright 2020 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.
+
+// Flags: --throws
+
+function main() {
+  function g() {
+    function h() {
+      f;
+    }
+    {
+      function f() {}
+    }
+    f;
+    throw new Error();
+  }
+  g();
+}
+main();