Semantic checker store conformance pass/fail info in a separate file

[overlookmotel]

#5976 added a structured test suite for Semantic.

As discussed in https://github.com/oxc-project/oxc/pull/5976#issuecomment-2368477213, currently it records whether the tests pass or fail in the .snap files. e.g. nested-assignment.snap

I think this is not ideal because I am worried that if details of test fails are hidden away there, they may never get fixed.

I can imagine a scenario like this: Someone makes a PR that breaks a test. They say "I'll fix that test in a follow-up". But they forget to do it, and because it's hidden away in one .snap file out of 290, no-one notices, and the bug lives on unfixed forever.

@DonIsaac said he'd make that change in a follow-up PR.