This extends EnumSet by
1) adding element-wise operations (without first creating an EnumSet of
   that element in the caller),
2) adding arithmetic assignment operators, and
3) adding a subtraction operation which removes all elements in another
   EnumSet, or a single element.

R=mlippautz@chromium.org

Change-Id: Ibe694e9e111e506ad09cf9729fa0b0ba38430b79
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2071874
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66451}