Allow static virtual members in CA1000

[RenderMichael]

Fixes #7126

[RenderMichael]

I wasn't sure how to specify the test as C# 11+ and .NET 7+, so I just set those diagnostics as expected.

Let me know if I should do it differently.

edit: I found a better way

[codecov]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (8d8ac7d) 96.44% compared to head (9d0b999) 96.44%.
Report is 8 commits behind head on main.

❗ Current head 9d0b999 differs from pull request most recent head 9358402. Consider uploading reports for the commit 9358402 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #7142   +/-   ##
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  Coverage   96.44%   96.44%           
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  Files        1413     1413           
  Lines      337719   337737   +18     
  Branches    11177    11178    +1     
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+ Hits       325700   325724   +24     
+ Misses       9200     9194    -6     
  Partials     2819     2819           

[mavasani]

Can we condition the entire test method on NET7_OR_GREATER?

[RenderMichael]

Although the test suite itself runs in .NET 8, when I run the test without the #if I get diagnostics about the C# and .NET versions being insufficient

Diagnostics:
// /0/Test0.cs(5,23): hidden CA1000: Do not declare static members on generic types
VerifyCS.Diagnostic().WithSpan(5, 23, 5, 37).WithArguments("AbstractMember"),
// /0/Test0.cs(5,40): error CS8919: Target runtime doesn't support static abstract members in interfaces.
DiagnosticResult.CompilerError("CS8919").WithSpan(5, 40, 5, 43),
// /0/Test0.cs(7,27): hidden CA1000: Do not declare static members on generic types
VerifyCS.Diagnostic().WithSpan(7, 27, 7, 40).WithArguments("VirtualMember"),
// /0/Test0.cs(7,44): error CS8919: Target runtime doesn't support static abstract members in interfaces.
DiagnosticResult.CompilerError("CS8919").WithSpan(7, 44, 7, 46),

I know we can specify the C# version to test against but I could not figure out if there's a way to set the .NET version. I didn't bother setting the C# version because .NET 7 implies C# 11.

[RenderMichael]

It turns out the #if was causing nothing to be generated (since the .NET version we're testing with is less than 7).

So I specified C# 11 and added expected diagnostics about .NET 7 features. It doesn't look very pleasant, if there's a more elegant way I'd be happy to improve it.

[RenderMichael]

OK I figured out how to specify .NET 6. Thank you for bearing with my learning, I'm fairly new to this codebase.