Roll Clang on Windows 201860:202050

This picks up Warren's CGRecordLayoutBuilder rewrite.

BUG=none
TBR=rnk@chromium.org

Review URL: https://codereview.chromium.org/178343003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252959 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 252959