[Testing] Allow Capitalized name in CompareBeforeAfter

[vinx13]

This PR allows to use capitalized variable name Before and Expected in CompareBeforeAfter. When before / after are classes or ir module, using capitalized variable names is more consistent with python naming convention.

cc @Lunderberg

[tvm-bot]

Thanks for contributing to TVM! Please refer to the contributing guidelines https://tvm.apache.org/docs/contribute/ for useful information and tips. Please request code reviews from Reviewers by @-ing them in a comment.

• No users to tag found in teams: testing _{See #10317 for details}

_{Generated by tvm-bot}

[Lunderberg]

Looks good, just one change to avoid accidental misuse. I like the change, and I'm always unsure how to name a @I.ir_module-annotated class. On the one hand, it looks like a class definition, but on the other hand, it produces something that acts more like a variable. Supporting both sounds reasonable to me.

[Lunderberg]

Can we add an assert that at most one of the two options are present?

[Lunderberg]

I'm not sure if should be that strong of an assert, as that would prevent defining an intermediate test that defines transform and expected, but doesn't define before. This could be useful for defining several tests that should all normalize to produce the same result. This would also break existing cases where the transform is defined, then used across several tests in a file.

What if instead, we were to assert that no duplicates names exist?

assert len([getattr(cls,name) for name in ['before','Before'] if hasattr(cls,name)]) <= 1
assert len([getattr(cls,name) for name in ['expected','Expected'] if hasattr(cls,name)]) <= 1

[Lunderberg]

Thank you for making the changes, and LGTM!