Bug: `SpecCompute::compute` panics

[emmyoh]

I've found that sometimes SpecCompute::compute causes the following panic:

thread 'main' panicked at library/alloc/src/raw_vec.rs:25:5:
capacity overflow

Not sure why exactly, but it does.

[psiphi75]

Strange, is there a specific input that causes it?

[emmyoh]

@psiphi75 Just seeing your reply now! Sadly, can't remember.