[release/11.0.1xx-preview6] Source code updates from microsoft/vstest

[dotnet-maestro]

Note

This is a codeflow update. It may contain both source code changes from
the source repo
as well as dependency updates. Learn more here.

This pull request brings the following source code changes

From https://github.com/microsoft/vstest

• Subscription: c0551ad6-4e9e-42b2-984e-5ef429660e62
• Build: 20260626.3 (320384)
• Date Produced: June 26, 2026 2:20:55 PM UTC
• Commit: 347cdb9131ce271827b95d83048159e6e6f11137
• Commit Diff: 385d75d...347cdb9
• Branch: main

Diff the source with this PR branch

darc vmr diff --name-only https://github.com/microsoft/vstest:347cdb9131ce271827b95d83048159e6e6f11137..https://github.com/dotnet/dotnet:darc-release/11.0.1xx-preview6-a98fcacd-0d3f-4981-a91e-ba7c0afcc0d9

[dotnet-maestro]

Note

PRs from original repository included in this codeflow update:

• Suggest Microsoft.NET.Test.Sdk when a managed test project brings no testhost microsoft/vstest#16169
• [efficiency-improver] perf: pre-allocate List(T) capacity in DiscoveryResultCache and TestRunCache microsoft/vstest#16165

💡 You may consult the FAQ for more information or tag @dotnet/prodconsvcs for assistance.

[dotnet-maestro]

Note

PRs from original repository included in this codeflow update:

• Fix x86 testhost loading mismatched x64 hostfxr (0x800700C1) when run via vstest.console.exe directly (#16151) microsoft/vstest#16156

💡 You may consult the FAQ for more information or tag @dotnet/prodconsvcs for assistance.