Prior to this CL, jsregexp contains a bunch of things that are slightly
related but would be cleaner in separate files, including: AST-to-Node
transformations, the compiler implementation, and a debugging printer.

This CL extracts AST-to-Node transformations.

Bug: v8:9359
Change-Id: I030cfca5c40cfd72e3a7abe2188e4654cfe2277c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1655303
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62148}