Make FileInfo/DirectoryInfo.Name lazy

[stephentoub]

We can delay the string allocation until it's actually requested.

Separated out of the already-approved #73942.

[ghost]

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Issue Details

---

We can delay the string allocation until it's actually requested.

Separated out of the already-approved #73942.

Author:	stephentoub
Assignees:	stephentoub
Labels:	area-System.IO
Milestone:	-

[danmoseley]

Failures related to the current upload issues

[adamsitnik]

LGTM!

[danmoseley]

#74049
also this infra flakiness - I'll paste the info for future discovery, but not open an issue since it's not worth investigation unless it starts happening repeatedly..

NuGet.Protocol.Core.Types.FatalProtocolException : Unable to load the service index for source https://api.nuget.org/v3/index.json.
---- System.Net.Http.HttpRequestException : An error occurred while sending the request.
-------- System.IO.IOException : Unable to write data to the transport connection: Broken pipe.
------------ System.Net.Sockets.SocketException : Broken pipe
Stack Trace
   at NuGet.Protocol.ServiceIndexResourceV3Provider.GetServiceIndexResourceV3(SourceRepository source, DateTime utcNow, ILogger log, CancellationToken token)
   at NuGet.Protocol.ServiceIndexResourceV3Provider.TryCreate(SourceRepository source, CancellationToken token)
   at NuGet.Protocol.Core.Types.SourceRepository.GetResourceAsync[T](CancellationToken token)
   at NuGet.Protocol.DependencyInfoResourceV3Provider.TryCreate(SourceRepository source, CancellationToken token)
   at NuGet.Protocol.Core.Types.SourceRepository.GetResourceAsync[T](CancellationToken token)
   at Microsoft.CodeAnalysis.Testing.ReferenceAssemblies.GetPackageDependenciesAsync(PackageIdentity packageIdentity, NuGetFramework targetFramework, ImmutableArray`1 repositories, SourceCacheContext cacheContext, ILogger logger, Builder dependencies, CancellationToken cancellationToken) in /_/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/ReferenceAssemblies.cs:line 569
   at Microsoft.CodeAnalysis.Testing.ReferenceAssemblies.ResolveCoreAsync(String language, CancellationToken cancellationToken) in /_/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/ReferenceAssemblies.cs:line 227
   at Microsoft.CodeAnalysis.Testing.ReferenceAssemblies.ResolveAsync(String language, CancellationToken cancellationToken) in /_/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/ReferenceAssemblies.cs:line 197
   at Microsoft.CodeAnalysis.Testing.ReferenceAssemblies.ResolveAsync(String language, CancellationToken cancellationToken) in /_/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/ReferenceAssemblies.cs:line 174
   at Microsoft.CodeAnalysis.Testing.AnalyzerTest`1.CreateSolutionAsync(ProjectId projectId, EvaluatedProjectState projectState, CancellationToken cancellationToken) in /_/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs:line 1235
   at Microsoft.CodeAnalysis.Testing.AnalyzerTest`1.CreateProjectImplAsync(EvaluatedProjectState primaryProject, ImmutableArray`1 additionalProjects, CancellationToken cancellationToken) in /_/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs:line 1050
   at Microsoft.CodeAnalysis.Testing.AnalyzerTest`1.CreateProjectAsync(EvaluatedProjectState primaryProject, ImmutableArray`1 additionalProjects, CancellationToken cancellationToken) in /_/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs:line 1029
   at Microsoft.CodeAnalysis.Testing.AnalyzerTest`1.GetSolutionAsync(EvaluatedProjectState primaryProject, ImmutableArray`1 additionalProjects, IVerifier verifier, CancellationToken cancellationToken) in /_/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs:line 1007
   at Microsoft.CodeAnalysis.Testing.AnalyzerTest`1.GetSortedDiagnosticsAsync(EvaluatedProjectState primaryProject, ImmutableArray`1 additionalProjects, ImmutableArray`1 analyzers, IVerifier verifier, CancellationToken cancellationToken) in /_/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs:line 890
   at Microsoft.CodeAnalysis.Testing.AnalyzerTest`1.VerifyDiagnosticsAsync(EvaluatedProjectState primaryProject, ImmutableArray`1 additionalProjects, DiagnosticResult[] expected, IVerifier verifier, CancellationToken cancellationToken) in /_/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs:line 273
   at Microsoft.CodeAnalysis.Testing.CodeFixTest`1.RunImplAsync(CancellationToken cancellationToken) in /_/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.CodeFix.Testing/CodeFixTest`1.cs:line 304
   at Microsoft.CodeAnalysis.Testing.AnalyzerTest`1.RunAsync(CancellationToken cancellationToken) in /_/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs:line 181
   at System.Text.RegularExpressions.Tests.CSharpCodeFixVerifier`2.VerifyCodeFixAsync(String source, String fixedSource, ReferenceAssemblies references) in /_/src/libraries/System.Text.RegularExpressions/tests/FunctionalTests/CSharpCodeFixVerifier`2.cs:line 36
   at System.Text.RegularExpressions.Tests.CSharpCodeFixVerifier`2.VerifyAnalyzerAsync(String source, ReferenceAssemblies references) in /_/src/libraries/System.Text.RegularExpressions/tests/FunctionalTests/CSharpCodeFixVerifier`2.cs:line 25
   at System.Text.RegularExpressions.Tests.UpgradeToGeneratedRegexAnalyzerTests.NoDiagnosticsForNet60(InvocationType invocationType) in /_/src/libraries/System.Text.RegularExpressions/tests/FunctionalTests/UpgradeToGeneratedRegexAnalyzerTests.cs:line 159
--- End of stack trace from previous location ---

[DrewScoggins]

Arm64-Ubuntu Improvements: dotnet/perf-autofiling-issues#8018