20% more memory use starting in `7.0.0-dev.20250724.1`

[walkerdb]

Context: we run tsgo on a large private monorepo, and recently tried updating to the latest release. After updating tsgo our CI runners consistently crashed due to out of memory errors.

After some debugging we narrowed it down to some change in the 7.0.0-dev.20250724.1 release:

• in 7.0.0-dev.20250723.1: ~25gb max ram used (profile)
• in 7.0.0-dev.20250724.1: ~30gb max ram used (profile)

Running pprof -diff_base on the two memory profiles seems to indicate that ~4gb additional ram is going to Set Add functions in the new version?

We can't share code for a repro but I'm happy to run more profiles if there's any additional data that would be useful for debugging.

[walkerdb]

for comparison, normal typescript 5.8 typecheck uses ~22gb ram total on our repo.

[joshcartme]

Same caveat as I mention there, it's not nearly as pronounced as you're seeing here, but I can repro this with the kibana codebase as described in #1520 (comment)