Oh no, we reached the max heap size again

That's pretty bad, the library should not take >6GB to typecheck. The memory usage graphs we have are useless, since I set a big pre-allocated buffer to speed up typechecking. I'll probably need to bisect the library to see if it's some rogue formalization bug, or if the library is inherently this big now.

Originally posted by @VojtechStep in #1560 (comment)