[wasm][CoreCLR] Enable passing System.Runtime.Tests on wasm

[radekdoulik]

Note

This PR description was AI/Copilot-generated.

Summary

Enable 44 previously-disabled System.Runtime.Tests on browser/wasm CoreCLR interpreter by removing unnecessary [ActiveIssue] and [SkipOnPlatform] attributes added in #122980.

Changes

Removed 44 attributes across 15 test these tests pass on the wasm interpreter without issues.files

Replaced [ActiveIssue] with proper platform detection for tests that require multithreading:
[ConditionalClass(..., uses Task.Run() + infinite loop that deadlocks on single-threaded wasmIsMultithreadingSupported)]
added IsMultithreadingSupported to usesThread.Start()ConditionalFact

10 [ActiveIssue] attributes remain for tests with genuine failures on wasm:

• GC finalizer tests ( no finalizer thread on single-threaded wasm4)
  int saturation bug
• ModuleTests ( Module.FullyQualifiedName/Name returns <Unknown>2)
• DateTimeTests ( System.Runtime.Serialization.Formatters not available1)
• RuntimeFeatureTests ( IsDynamicCodeSupported is false (no JIT)1)

Validation

Full test suite runs locally in ~7 minutes with 68,025 tests, 0 failures, 94 skipped.

Triage

See libraries-tests-triage.md in the test directory for detailed analysis of remaining disabled tests.

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing, @pavelsavara
See info in area-owners.md if you want to be subscribed.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Enables previously-disabled System.Runtime.Tests on browser/wasm CoreCLR interpreter by removing unnecessary [ActiveIssue] / [SkipOnPlatform] annotations and replacing a couple of skips with capability-based platform detection (multithreading).

Changes:

• Removed a broad set of wasm/browser CoreCLR test disables ([ActiveIssue], [SkipOnPlatform]) where tests now pass.
• Switched threading-dependent tests from issue-based disables to PlatformDetection.IsMultithreadingSupported conditions.
• Added a triage doc summarizing remaining wasm/CoreCLR interpreter test gaps and their root causes.

Reviewed changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/libraries/System.Runtime/tests/System.Runtime.Tests/libraries-tests-triage.md	New triage document tracking remaining skipped/disabled tests on browser/wasm CoreCLR interpreter.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/UInt128Tests.cs	Removes wasm/browser CoreCLR [ActiveIssue] to re-enable parsing tests.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/Threading/PeriodicTimerTests.cs	Removes wasm/browser CoreCLR [ActiveIssue] to re-enable PeriodicTimer tests.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/StringTests.cs	Removes wasm/browser CoreCLR [ActiveIssue] to re-enable a GetHashCode argument-validation test.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/SingleTests.GenericMath.cs	Removes wasm/browser CoreCLR [ActiveIssue] from ConvertToIntegerNativeTest.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/Runtime/JitInfoTests.cs	Replaces [ActiveIssue] with ConditionalFact including multithreading capability detection.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/Runtime/ControlledExecutionTests.cs	Replaces [ActiveIssue] with ConditionalClass gated on multithreading support.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/Reflection/InvokeWithRefLikeArgs.cs	Removes browser skip to re-enable ref-like reflection invocation test.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/Numerics/TotalOrderIeee754ComparerTests.cs	Removes wasm/browser CoreCLR [ActiveIssue] to re-enable invalid-significand test.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/Int128Tests.cs	Removes wasm/browser CoreCLR [ActiveIssue] to re-enable parsing tests.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/HalfTests.cs	Removes wasm/browser CoreCLR [ActiveIssue] to re-enable UTF8 span parsing test.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/HalfTests.GenericMath.cs	Removes wasm/browser CoreCLR [ActiveIssue] to re-enable parsing tests in generic-math suite.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/GCTests.cs	Removes wasm/browser CoreCLR [ActiveIssue] to re-enable negative-size allocation test.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/DoubleTests.GenericMath.cs	Removes wasm/browser CoreCLR [ActiveIssue] from ConvertToIntegerNativeTest.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/DelegateTests.cs	Removes wasm/browser CoreCLR [ActiveIssue] to re-enable DynamicInvoke default-parameter tests.
src/libraries/System.Runtime/tests/System.Runtime.Tests/System/DecimalTests.cs	Removes wasm/browser CoreCLR [ActiveIssue] across multiple decimal tests/classes.