{IsAligned} is defined twice with exactly the same signature and
implementation: once in base/macros.h, once in utils.h.

This CL removes the definition from utils.h.
Note that utils.h includes macros.h, so no further changes are needed.

R=mlippautz@chromium.org

Bug: v8:8238
Change-Id: I589b00c01619d054ff39c717f728a2351b6c32ea
Reviewed-on: https://chromium-review.googlesource.com/c/1280206
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56632}