It is not a review, but I had time to run the TTC tests against the pull request (using GHC 8.10.6 on Linux), and all tests pass. The tests mostly deal with conversion to/from other types and therefore do not test many of the changes, but I am posting this to show support and appreciation for your efforts. Thank you!
Bumping this. Since
text is a boot library, we have a limited timeframe to get this merged before GHC 9.4 feature freeze. I understand that the branch looks intimidating, but you can pick any commit in the branch and review it separately - most of them work on orthogonal performance issues and can be analysed in isolation.