Remove stray unicode character

A stray 0xfeff character was accidentally added in
https://crrev.com/c/2952864, causing compilation problems on some
platforms. This CL removes it.

In case your diff looks empty, this is the change:
-<feff>// Copyright 2012 the V8 project authors. All rights reserved.
+// Copyright 2012 the V8 project authors. All rights reserved.

It was generated via
> git checkout -p 9c904a8f^ src/utils/alloca*.cc

R=leszeks@chromium.org

Bug: v8:11968
Change-Id: Ief3eba7875383c4a4c4238a4af47083304fc9782
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3038526Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75788}

src/utils/allocation.cc

-// Copyright 2012 the V8 project authors. All rights reserved.
+// Copyright 2012 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.