Fix various failing tests

[aminya]

No description provided.

[rotu]

I tried to give targeted and actionable feedback but it seems to have been ignored. @aminya, @bluca, in the spirit of open source, how can I better contribute to this project?

[aminya]

@rotu I think you have misread the code. I didn't remove the .gc calls. They were just indented. Changing the GC calls is out of the scope of this PR.

[rotu]

@rotu I think you have misread the code. I didn't remove the .gc calls. They were just indented. Changing the GC calls is out of the scope of this PR.

@aminya oops - you're right you didn't remove them. BTW, these calls make the garbage collector run synchronously, so if any of the tests are at all timing-sensitive, you might notice some weirdness, especially since things are running in parallel now.

[aminya]

@rotu Some of the remaining failing tests are related to GC, but we have to fix them. Take a look at Issue 466 for context.