Merge pull request #2 from grovesj005/azure-pipelines2

Merge pull request #1 from grovesj005/auto-cargo

Auto merge of rust-lang#14793 - epage:test-compare, r=weihanglo

docs(test):  Document Execs assertions based on port effort

### What does this PR try to resolve?

Closes rust-lang#14039

A lot of this was pulled from rust-lang#14039, common assertions people need to write, and from seeing people not noticing features that exist.

I'm leaving behind the `contains` assertions, rather than finding a way to make them work with snapbox.  Thankfully, snapbox is designed to let people build their own thing (see rust-lang#14790).  I considered reusing snapbox's `[..]` matches but the code here is pretty minimal, the logic is similar enough, and I don't have a great abstraction for snapbox for it.  If there was more of a need, I'd make something work in snapbox.  As such, the `contains` assertions are no longer deprecated.

While doing this last pass through, I did some polish on the code as well.

### How should we test and review this PR?

### Additional information

Author: grovesj005