Port 7c08633b

Original Commit Message:

    Replace 'virtual' by 'override' when overriding methods.
    This uncovered one method which was unnecessarily virtual:
    {RegExpMacroAssemblerARM64::CheckCharacters}.

R=clemensb@chromium.org, joransiu@ca.ibm.com, junyan@redhat.com, midawson@redhat.com
BUG=
LOG=N

Change-Id: I542aeae836b5b78284291ed39844a5c166ed06ad
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3208811Reviewed-by: Junliang Yan <junyan@redhat.com>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/main@{#77269}