524fdc13a9
This is a reland of b71d2d9996
Original change's description:
> [llvm] Add initial scaffolding
>
> This change adds the gclient and GN changes needed to build
> an executable using LLVM in the Dart tree as well as a basic
> testing framework based on llvm-lit.
>
> Change-Id: I9009a98ff95043cc3754966f31697ba7f1712310
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/106434
> Commit-Queue: Jake Ehrlich <jakehehrlich@google.com>
> Reviewed-by: Alexander Thomas <athom@google.com>
> Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Change-Id: Ib3cd3299ed463133616c666285f9a58fa387b5bd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/107829
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Jake Ehrlich <jakehehrlich@google.com>