Analyzers cause significant build perf hit

[mthjones]

Including these analyzers in the build causes a significant performance hit. In one solution, the performance hit is a ~50% increase in build time (a ~100% increase in csc.exe time).

Breakdown of time spent in analyzers from this package (from building with ReportAnalyzer=true):

D2L.CodeStyle.Analyzers

1:06.961   D2L.CodeStyle.Analyzers, Version=0.157.0.0, Culture=neutral, PublicKeyToken=null
    D2L.CodeStyle.Analyzers.Immutability.ImmutabilityAnalyzer = 13.889 s
    D2L.CodeStyle.Analyzers.ApiUsage.ServiceLocator.OldAndBrokenServiceLocatorAnalyzer = 11.500 s
    D2L.CodeStyle.Analyzers.ApiUsage.DangerousMemberUsages.DangerousMemberUsagesAnalyzer = 10.690 s
    D2L.CodeStyle.Analyzers.Immutability.ReadOnlyParameterAnalyzer = 6.052 s
    D2L.CodeStyle.Analyzers.ApiUsage.ConstantAttributeAnalyzer = 5.727 s
    D2L.CodeStyle.Analyzers.ApiUsage.Events.EventPublisherEventTypesAnalyzer = 3.483 s
    D2L.CodeStyle.Analyzers.ApiUsage.Events.EventHandlerLoaderTypesAnalyzer = 3.042 s
    D2L.CodeStyle.Analyzers.ApiUsage.Configs.ConfigViewerAnalyzer = 2.804 s
    D2L.CodeStyle.Analyzers.Language.DefaultValueConsistencyAnalyzer = 1.951 s
    D2L.CodeStyle.Analyzers.Language.RequireNamedArgumentsAnalyzer = 1.816 s
    D2L.CodeStyle.Analyzers.Immutability.StatelessFuncAnalyzer = 1.017 s
    D2L.CodeStyle.Analyzers.ApiUsage.Events.EventHandlersDisallowedListAnalyzer = 931 ms
    D2L.CodeStyle.Analyzers.ApiUsage.ServiceLocator.SingletonLocatorAnalyzer = 710 ms
    D2L.CodeStyle.Analyzers.ApiUsage.DependencyInjection.DependencyRegistrationsAnalyzer = 706 ms
    D2L.CodeStyle.Analyzers.ApiUsage.LaunchDarkly.FeatureDefinitionAnalyzer = 644 ms
    D2L.CodeStyle.Analyzers.ApiUsage.Logging.LoggingExecutionContextScopeBuilderAnalyzer = 590 ms
    D2L.CodeStyle.Analyzers.ApiUsage.Events.EventTypesAnalyzer = 576 ms
    D2L.CodeStyle.Analyzers.ApiUsage.Serialization.SerializerAttributeAnalyzer = 511 ms
    D2L.CodeStyle.Analyzers.ApiUsage.SystemCollectionsImmutable.ImmutableCollectionsAnalyzer = 164 ms
    D2L.CodeStyle.Analyzers.Contract.NotNullAnalyzer = 54 ms
    D2L.CodeStyle.Analyzers.ApiUsage.JsonParamBinderAttribute.JsonParamBinderAnalyzer = 24 ms
    D2L.CodeStyle.Analyzers.Language.StructShouldBeReadonlyAnalyzer = 7 ms
    D2L.CodeStyle.Analyzers.Language.AwaitedTasksAnalyzer = 5 ms
    D2L.CodeStyle.Analyzers.Build.MandatoryReferencesAnalyzer = 2 ms
    D2L.CodeStyle.Analyzers.ApiUsage.ContentPhysicalPaths.ILegacyLpContentDirectoryFullNameAnalyzer = 0 ms
    D2L.CodeStyle.Analyzers.ApiUsage.ContentPhysicalPaths.ILegacyLpContentFilePhysicalPathAnalyzer = 0 ms
    D2L.CodeStyle.Analyzers.ApiUsage.ContentPhysicalPaths.ILpContentFilePhysicalPathAnalyzer = 0 ms
    D2L.CodeStyle.Analyzers.ApiUsage.RpcAnalyzer = 0 ms
    D2L.CodeStyle.Analyzers.Language.ClassShouldBeSealedAnalyzer = 0 ms

D2L.CodeStyle.TestAnalyzers

8.914 s   D2L.CodeStyle.TestAnalyzers, Version=0.25.0.0, Culture=neutral, PublicKeyToken=null
    D2L.CodeStyle.TestAnalyzers.ServiceLocator.CustomTestServiceLocatorAnalyzer = 3.176 s
    D2L.CodeStyle.TestAnalyzers.NUnit.ConfigTestSetupStringsAnalyzer = 2.433 s
    D2L.CodeStyle.TestAnalyzers.NUnit.TestAttributeAnalyzer = 1.036 s
    D2L.CodeStyle.TestAnalyzers.NUnit.TestCaseSourceStringsAnalyzer = 913 ms
    D2L.CodeStyle.TestAnalyzers.NUnit.CategoryAnalyzer = 905 ms
    D2L.CodeStyle.TestAnalyzers.NUnit.ValueSourceStringsAnalyzer = 436 ms

[mthjones]

There is some indication that switching to IOperation-based analyzers may significantly improve performance: dotnet/roslyn#46349

[mthjones]

At least some of the perf issues may stem from the reason this diagnostic exists. We use Compilation.GetSemanticModel in the two slowest analyzers in D2L.CodeStyle.Analyzers and the slowest one in D2L.CodeStyle.TestAnalyzers.

May be worth investigating if these can be replaced with one of the suggestions provided.