Copy irregexp related code from V8.

Copy irregexp related code from V8.

This "syntactic" change copies the irregexp code from V8 r24065 to Dart.
Compared to the V8 files the only changes are that the files have been
suitably renamed, headers and footers have been updated, and most of the
unneeded code has been replaced by a 'SNIP' marker. None of the files
are added to the build and they cannot compile. Integration with the
Dart VM is done in a follow-up CL [1].

[1]: https://codereview.chromium.org/683433003/

BUG=
R=iposva@google.com

Committed: https://code.google.com/p/dart/source/detail?r=41455

[zerny-google, 2014-10-28 08:29:56]

zerny@google.com changed reviewers:
+ fschneider@google.com, iposva@google.com, vegorov@google.com

[Ivan Posva, 2014-11-03 08:44:43]

LGTM

Let's land this so we have a good overview of the changes needed in the irregexp
files to actually make them compile in the other CL.

-Ivan

[zerny-google, 2014-11-03 10:00:46]

Committed patchset #2 (id:20001) manually as 41455.