Reuse linker tests in analyzer

[sbomer]

This is a tracking issue that I'll try to keep updated to reflect the work left to get to 100% coverage of the linker's warning validation in the analyzer.

We already have some shared tests, and #2292 improves the validation (especially for UnrecognizedReflectionAccessPattern), but there are still some discrepancies that prevent sharing of tests. The one I'm aware of is:

• [ ] Ensure analyzer and linker use same signature format
  • This is required for a lot of the UnrecognizedReflectionAccessPattern attributes
  • No namespaces in parameter types
  • No namespace or declaring type in callee method
  • Use spaces between parameters

Once that's fixed we should start turning on various tests and fixing any remaining discrepancies as we uncover them:

• Enable linker tests for DAM without dataflow ([feature/damAnalyzer] Enable a few linker DAM tests for analyzer #2307, [DAM analyzer] Add support for properties and enable more tests #2390)

  • A good portion of the tests in https://github.com/dotnet/linker/tree/main/test/Mono.Linker.Tests.Cases/DataFlow probably don't require dataflow analysis.

• Enable linker dataflow tests (https://github.com/dotnet/linker/pull/2360/files)

  • Depends on analyzer support for dataflow analysis
  • We should aim to get most of the tests in running with the analyzer.

• Move analyzer tests into shared linker testcases

  • We can keep a few analyzer-only tests as a sanity check, but once we have confidence in the validation, most of the tests should be shared.

Other test sharing that we can start doing, which doesn't depend on the UnrecognizedReflectionAccessPattern as far as I know:

• Share RequiresCapability tests
  • RequiresAssemblyFiles analyzer should be able to reuse testcases for RequiresUnreferencedCode.
  • @tlakollo already renamed the test to be agnostic to the attribute name: Rename RequiresUnreferencedCode to Requires  #2301
  • Need to add RequiresAssemblyFiles attribute and ExpectedWarnings produced by RequiresAssemblyFiles analyzer only

[sbomer]

I've updated the above with links to some of the completed work. Additionally, the following changes made it easier to share tests and give us increased confidence that the tests catch all disparities between the linker and analyzer:

• ExpectedWarning silences only one warning per attribute #2479
• [feature/damAnalyzer] Remove reflection access patterns from tests #2444

We don't really want to use the same signature format for linker and analyzer, so I've crossed out that item above. We have a tracking issue for it at #2406.

I think we can close this now. We are already sharing a good portion of the tests with the analyzer, and I'm not aware of any infrastructure issues preventing us from doing further sharing. The remaining work is just about analyzer parity, tracked in #2273.