RegExpImpl::Compile does a number of transformations that require
directly manipulating the internal representation of the regexp. For
example, when matching a (non-sticky, non-anchored) regular
expression, the pattern must be wrapped in .* so that it can match
anywhere in the input.

In the interest of moving towards a cleaner division between irregexp
and the outside world, it makes sense to move this code into
RegExpCompiler.

R=jgruber@chromium.org

Bug: v8:10406
Change-Id: I6da251c91c0016914a51480f80bb46c337fd0b23
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2140246Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67262}