GitLab

This change simplifies the implementation of base::CharTraits and adds a
specialization for wchar_t, leveraging clang's builtins if available.

Bug: None
Change-Id: Icedc3f8dc65a507552703ac5a30e062cc248e847
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2596151Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Jan Wilken Dörrie <jdoerrie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#838209}