Bug 1592302: Part 1: Import regexp directory from v8 r=mgaudet,mhoye

Irregexp is the V8 regular expression engine. SpiderMonkey contains a heavily modified copy of a previous version of irregexp (under js/src/irregexp). The modifications make it very difficult to incorporate upstream changes. To catch up on webcompat, we are re-importing a fresh copy of irregexp, with the intent of tracking upstream more closely.

This patch imports the source files that can be found here:

https://github.com/v8/v8/tree/2599d3cc208a3a4873be517285220abd8416c3d7/src/regexp

... with the following files removed:

regexp/OWNERS
regexp/regexp.cc
regexp/regexp-utils.cc
regexp/regexp-utils.h
regexp/regexp-macro-assembler-arch.h
regexp/ia32/*
regexp/x64/*
regexp/mips/*
regexp/mips64/*
regexp/arm/*
regexp/arm64/*
regexp/s390/*
regexp/ppc/*

In addition, a VERSION file has been added pointing to the most recently imported V8 github revision, and js/src/new-regexp has been added to the list of directories covered by the V8 license in licenses.html.

Differential Revision: https://phabricator.services.mozilla.com/D51928

--HG--
extra : moz-landing-system : lando