[Feature Request] [stdlib] Add `assert_aborts()`

[martinvuyk]

Review Mojo's priorities

• [X] I have read the roadmap and priorities and I believe this request falls within the priorities.

What is your request?

As title.

What is your motivation for this change?

A way to test if a program aborts to avoid unsafe and undefined behavior

Any other details?

It could be done by having it require a closure to be passed in and somehow spin up an isolated process